From fb551d7220c2887a569a9db1e17357ad54801b28 Mon Sep 17 00:00:00 2001
From: Connor Olding <cloningdonor@gmail.com>
Date: Sun, 9 Oct 2022 12:39:27 -0700
Subject: [PATCH] cosmo: merge upstream dash into unbourne shell and distribute
 it

---
 build-all                      |    4 +-
 cosmo/Dockerfile               |   34 +-
 cosmo/unbourne-backports.patch | 1671 ++++++++++++++++++++++++++++++++
 3 files changed, 1692 insertions(+), 17 deletions(-)
 create mode 100644 cosmo/unbourne-backports.patch

diff --git a/build-all b/build-all
index e6e273d..4f41493 100755
--- a/build-all
+++ b/build-all
@@ -35,8 +35,8 @@ dbg_retrieve() { : \
  && podman build -t cosmo-yices     cosmo-yices \
 \
  && bin=/cosmopolitan/bin \
- && yes_retrieve cosmo $bin/ape $bin/awk.com $bin/gzip.com \
-    $bin/make.com $bin/sed.com $bin/unzip.com $bin/zip.com \
+ && yes_retrieve cosmo $bin/ape $bin/awk.com $bin/gzip.com $bin/make.com \
+    $bin/sed.com $bin/unbourne.com $bin/unzip.com $bin/zip.com \
  && dbg_retrieve cosmo-kuroko /bin/kuroko.com \
  && dbg_retrieve cosmo-muon /bin/muon.com \
  && dbg_retrieve cosmo-perl /bin/perl.com \
diff --git a/cosmo/Dockerfile b/cosmo/Dockerfile
index 2e91e9d..94d6d12 100644
--- a/cosmo/Dockerfile
+++ b/cosmo/Dockerfile
@@ -20,7 +20,8 @@ WORKDIR /cosmopolitan
 # tell makefiles to be less noisy, also use /tmp:
 ENV V=0 COLUMNS=80 TMPDIR=/tmp
 
-COPY --chmod=0755 --from=localhost/notwa-util /nu/shed /usr/bin/
+COPY unbourne-backports.patch /cosmopolitan/
+COPY --chmod=0755 --from=localhost/notwa-util /nu/ /usr/bin/
 RUN : \
 # allow optimized builds to be more portable, so the container is too. \
  && shed build/config.mk 's/-march=native/-march=haswell -mno-pclmul -mtune=generic/' \
@@ -46,14 +47,15 @@ RUN : \
     commit "$COSMO_COMMIT" \
     flavor "$COSMO_FLAVOR" \
     mode "$mode" \
+# apply patches from dash to unbourne shell \
+ && /usr/bin/busybox patch -p1 -i unbourne-backports.patch \
 # make calling make a little shorter (don't put this in distrib!) \
  && ln -s build/bootstrap/make.com make \
 ;
 
 # finally start building
-
 RUN --mount=type=tmpfs,target=/tmp : \
- && . ./env && o="o/$mode" a="$o/ape" b="$o/tool/build" t="$o/third_party" \
+ && . ./env && o="o/$mode" a="$o/ape" b="$o/tool/build" t="$o/third_party" e="$o/examples" \
  && ./make -j2 MODE="$mode" \
   "$a/ape-copy-self.o"      "$a/ape-no-modify-self.o" "$a/ape.elf"              \
   "$a/ape.lds"              "$a/ape.macho"            "$a/ape.o"                \
@@ -70,12 +72,13 @@ RUN --mount=type=tmpfs,target=/tmp : \
   "$b/zipobj.com"           \
 # these are essential too! \
  && ./make -j2 MODE="$mode" "$@" \
-  "$t/awk/awk.com"          "$t/sed/sed.com"          "$t/unzip/unzip.com"      \
-  "$t/zip/zip.com"          "$b/assimilate.com"       \
+  "$e/unbourne.com"         "$t/awk/awk.com"          "$t/sed/sed.com"          \
+  "$t/unzip/unzip.com"      "$t/zip/zip.com"          "$b/assimilate.com"       \
 ;
 
+# install the basics (no executable binaries besides ape.elf)
 RUN : \
- && . ./env && o="o/$mode" a="$o/ape" b="$o/tool/build" t="$o/third_party" \
+ && . ./env && o="o/$mode" a="$o/ape" b="$o/tool/build" t="$o/third_party" e="$o/examples" \
  && mkdir dist "dist/$flavor" "dist/$flavor/public" \
  && echo /dist >>.gitignore \
  && cp -t "dist/$flavor" \
@@ -94,10 +97,11 @@ RUN : \
   "$t/zlib/zconf.h"         "$t/zlib/zlib.h"          \
 ;
 
+# install the rest
 FROM builder AS distrib
 COPY --chmod=0755 --from=localhost/notwa-util /nu/dedupe /usr/bin/
 RUN --mount=type=tmpfs,target=/tmp : \
- && . ./env && o="o/$mode" a="$o/ape" b="$o/tool/build" t="$o/third_party" \
+ && . ./env && o="o/$mode" a="$o/ape" b="$o/tool/build" t="$o/third_party" e="$o/examples" \
  && find o -name '*.sym' -delete \
  && dedupe o/third_party/gcc /distrib/gcc/ \
     bin/x86_64-linux-musl-gcc \
@@ -108,14 +112,14 @@ RUN --mount=type=tmpfs,target=/tmp : \
 # discover .com files by uncommenting this command: \
 #&& find o -name '*.com' ! -type d -exec printf '%s\n' cp -t /tmp/bin {} + | sort && exit 1 \
  && cp -t /tmp/bin \
-  "$t/awk/awk.com"          "$t/make/make.com"        "$t/sed/sed.com"          \
-  "$t/unzip/unzip.com"      "$t/zip/zip.com"          "$b/ar.com"               \
-  "$b/assimilate.com"       "$b/cocmd.com"            "$b/compile.com"          \
-  "$b/cp.com"               "$b/echo.com"             "$b/fixupobj.com"         \
-  "$b/gzip.com"             "$b/mkdeps.com"           "$b/mkdir.com"            \
-  "$b/package.com"          "$b/pwd.com"              "$b/rm.com"               \
-  "$b/rollup.com"           "$b/symtab.com"           "$b/touch.com"            \
-  "$b/unbundle.com"         "$b/zipobj.com"           \
+  "$e/unbourne.com"         "$t/awk/awk.com"          "$t/make/make.com"        \
+  "$t/sed/sed.com"          "$t/unzip/unzip.com"      "$t/zip/zip.com"          \
+  "$b/ar.com"               "$b/assimilate.com"       "$b/cocmd.com"            \
+  "$b/compile.com"          "$b/cp.com"               "$b/echo.com"             \
+  "$b/fixupobj.com"         "$b/gzip.com"             "$b/mkdeps.com"           \
+  "$b/mkdir.com"            "$b/package.com"          "$b/pwd.com"              \
+  "$b/rm.com"               "$b/rollup.com"           "$b/symtab.com"           \
+  "$b/touch.com"            "$b/unbundle.com"         "$b/zipobj.com"           \
  && dedupe /tmp/bin /distrib/bin/ \
 #&& ln -s "../dist/$flavor/ape.elf" /distrib/bin/ape \
  && cp "dist/$flavor/ape.elf" /distrib/bin/ape \
diff --git a/cosmo/unbourne-backports.patch b/cosmo/unbourne-backports.patch
new file mode 100644
index 0000000..b80a841
--- /dev/null
+++ b/cosmo/unbourne-backports.patch
@@ -0,0 +1,1671 @@
+--- a/examples/unbourne.c
++++ b/examples/unbourne.c
+@@ -59,8 +59,8 @@
+   for decades thanks to a spark of brilliance from Ken Thompson.
+ 
+     git://git.kernel.org/pub/scm/utils/dash/dash.git
+-    fba95e9e4a5d0f1f1ac9f7d86557e47bc0e2656c
+-    Tue Jun 19 11:27:37 2018 -0400
++    057cd650a4edd5856213d431a974ff35c6594489
++    Fri Sep 03 15:00:58 2021 +0800
+ 
+   The UNBOURNE SHELL pays HOMAGE to the Stewards of House California:
+ 
+@@ -68,7 +68,7 @@
+     Derived from software contributed to Berkeley by Kenneth Almquist.
+ 
+     Copyright 1991,1993 The Regents of the University of California
+-    Copyright 1997-2018 Herbert Xu
++    Copyright 1997-2021 Herbert Xu
+     Copyright 1997 Christos Zoulas
+ 
+     Redistribution and use in source and binary forms, with or without
+@@ -183,6 +183,7 @@
+ /* exceptions */
+ #define EXINT   0
+ #define EXERROR 1
++#define EXEND   3
+ #define EXEXIT  4
+ 
+ /*
+@@ -207,7 +208,6 @@
+ #define CEOF      11
+ #define CCTL      12
+ #define CSPCL     13
+-#define CIGN      14
+ 
+ /* Syntax classes for is_ functions */
+ #define ISDIGIT 01
+@@ -216,13 +216,11 @@
+ #define ISUNDER 010
+ #define ISSPECL 020
+ 
+-#define SYNBASE 130
+-#define PEOF    -130
++#define SYNBASE 129
++#define PEOF    -129
+ 
+ #define EOF_NLEFT -99
+ 
+-#define PEOA -129
+-
+ #define BASESYNTAX (basesyntax + SYNBASE)
+ #define DQSYNTAX   (dqsyntax + SYNBASE)
+ #define SQSYNTAX   (sqsyntax + SYNBASE)
+@@ -345,6 +343,7 @@
+ #define VSTRIMLEFT     0x8
+ #define VSTRIMLEFTMAX  0x9
+ #define VSLENGTH       0xa
++/* VSLENGTH must come last. */
+ 
+ /* values of checkkwd variable */
+ #define CHKALIAS   0x1
+@@ -484,9 +483,10 @@
+ #define CUR_STOPPED 0
+ 
+ /* mode flags for dowait */
+-#define DOWAIT_NORMAL  0
+-#define DOWAIT_BLOCK   1
+-#define DOWAIT_WAITCMD 2
++#define DOWAIT_NONBLOCK    0
++#define DOWAIT_BLOCK       1
++#define DOWAIT_WAITCMD     2
++#define DOWAIT_WAITCMD_ALL 4
+ 
+ /* _rmescape() flags */
+ #define RMESCAPE_ALLOC 0x01
+@@ -570,7 +570,6 @@
+ #define CD_PHYSICAL 1
+ #define CD_PRINT    2
+ 
+-#define REALLY_CLOSED -3
+ #define EMPTY         -2
+ #define CLOSED        -1
+ #define PIPESIZE      4096
+@@ -711,10 +710,11 @@
+   struct strpush *prev; /* preceding string on stack */
+   char *prevstring;
+   int prevnleft;
+-  struct alias *ap; /* if push was associated with an alias */
+-  char *string;     /* remember the string since it may change */
+-  int lastc[2];     /* Remember last two characters for pungetc. */
+-  int unget;        /* Number of outstanding calls to pungetc. */
++  struct alias *ap;       /* if push was associated with an alias */
++  char *string;           /* remember the string since it may change */
++  struct strpush *spfree; /* Delay freeing so we can stop nested aliases. */
++  int lastc[2];           /* Remember last two characters for pungetc. */
++  int unget;              /* Number of outstanding calls to pungetc. */
+ };
+ 
+ /*
+@@ -731,6 +731,7 @@
+   char *buf;                  /* input buffer */
+   struct strpush *strpush;    /* for pushing strings at this level */
+   struct strpush basestrpush; /* so pushing one is fast */
++  struct strpush *spfree;     /* Delay freeing so we can stop nested aliases. */
+   int lastc[2];               /* Remember last two characters for pungetc. */
+   int unget;                  /* Number of outstanding calls to pungetc. */
+ };
+@@ -1055,8 +1056,8 @@
+ static int funcblocksize;  /* size of structures in function */
+ static int funcline;       /* start line of function, or 0 if not in one */
+ static int funcstringsize; /* size of strings in node */
+-static int gotsigchld;     /* received SIGCHLD */
+ static int initialpgrp;    /* pgrp of shell on invocation */
++static int inps4;          /* Prevent PS4 nesting. */
+ static int job_warning;
+ static int jobctl;
+ static int last_token;
+@@ -1083,6 +1084,7 @@
+ static struct ifsregion *ifslastp;  /* last struct in list */
+ static struct ifsregion ifsfirst;   /* first struct in list of ifs regions */
+ static struct jmploc *handler;
++static struct jmploc main_handler;
+ static struct job *curjob; /* current job */
+ static struct job *jobtab; /* array of jobs */
+ static struct localvar_list *localvar_stack;
+@@ -1099,8 +1101,10 @@
+ static struct Var *vartab[VTABSIZE];
+ static union node *redirnode;
+ static union yystype yylval;
++static unsigned closed_redirs; /* Bit map of currently closed file descriptors. */
+ static unsigned expdir_max;
+ static unsigned njobs; /* size of array */
++static volatile sig_atomic_t gotsigchld;  /* received SIGCHLD */
+ static volatile sig_atomic_t intpending;
+ static volatile sig_atomic_t pending_sig; /* last pending signal */
+ static struct alias *atab[ATABSIZE];
+@@ -1217,117 +1221,135 @@
+ 
+ /* syntax table used when not in quotes */
+ static const char basesyntax[] /* clang-format off */ = {
+-    CEOF,  CSPCL,   CWORD,   CCTL,    CCTL,  CCTL,  CCTL,  CCTL,    CCTL,
+-    CCTL,  CCTL,    CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CSPCL, CNL,   CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CSPCL, CWORD,   CDQUOTE, CWORD,   CVAR,  CWORD, CSPCL, CSQUOTE, CSPCL,
+-    CSPCL, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CSPCL, CSPCL,   CWORD,   CSPCL,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CBACK, CWORD,   CWORD,
+-    CWORD, CBQUOTE, CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD,
+-    CWORD, CWORD,   CSPCL,   CENDVAR, CWORD, CWORD
++    CEOF,    CWORD,   CCTL,    CCTL,  CCTL,  CCTL,  CCTL,    CCTL,  CCTL,
++    CCTL,    CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CSPCL, CNL,   CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CSPCL,
++    CWORD,   CDQUOTE, CWORD,   CVAR,  CWORD, CSPCL, CSQUOTE, CSPCL, CSPCL,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CSPCL,
++    CSPCL,   CWORD,   CSPCL,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CBACK, CWORD,   CWORD, CWORD,
++    CBQUOTE, CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CWORD,   CWORD,   CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD,
++    CWORD,   CSPCL,   CENDVAR, CWORD, CWORD
+ } /* clang-format on */;
+ 
+ /* syntax table used when in double quotes */
+ static const char dqsyntax[] /* clang-format off */ = {
+-    CEOF,  CIGN,    CWORD,     CCTL,    CCTL,  CCTL,  CCTL,  CCTL,  CCTL,
+-    CCTL,  CCTL,    CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CNL,   CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CCTL,    CENDQUOTE, CWORD,   CVAR,  CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CCTL,    CWORD,     CWORD,   CCTL,  CWORD, CCTL,  CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CCTL,
+-    CWORD, CWORD,   CCTL,      CWORD,   CCTL,  CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CCTL,  CBACK, CCTL,  CWORD,
+-    CWORD, CBQUOTE, CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD,   CWORD,     CENDVAR, CCTL,  CWORD
++    CEOF,    CWORD,     CCTL,    CCTL,  CCTL,  CCTL,  CCTL,  CCTL,  CCTL,
++    CCTL,    CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CNL,   CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CCTL,    CENDQUOTE, CWORD,   CVAR,  CWORD, CWORD, CWORD, CWORD, CWORD,
++    CCTL,    CWORD,     CWORD,   CCTL,  CWORD, CCTL,  CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CCTL,  CWORD,
++    CWORD,   CCTL,      CWORD,   CCTL,  CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CCTL,  CBACK, CCTL,  CWORD, CWORD,
++    CBQUOTE, CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD,     CENDVAR, CCTL,  CWORD
+ } /* clang-format on */;
+ 
+ /* syntax table used when in single quotes */
+-static const char sqsyntax[] = {
+-    CEOF,      CIGN,  CWORD, CCTL,  CCTL,  CCTL,  CCTL,  CCTL,  CCTL,  CCTL,  CCTL,  CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CNL,   CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CCTL,  CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CENDQUOTE, CWORD, CWORD, CCTL,  CWORD, CWORD, CCTL,  CWORD, CCTL,  CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CCTL,  CWORD, CWORD, CCTL,  CWORD, CCTL,  CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CCTL,      CCTL,  CCTL,  CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
+-    CWORD,     CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CCTL,  CWORD,
+-};
++static const char sqsyntax[] /* clang-format off */ = {
++    CEOF,  CWORD, CCTL,  CCTL,  CCTL,  CCTL,  CCTL,      CCTL,  CCTL,
++    CCTL,  CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CNL,   CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CCTL,  CWORD, CWORD, CWORD, CWORD, CWORD, CENDQUOTE, CWORD, CWORD,
++    CCTL,  CWORD, CWORD, CCTL,  CWORD, CCTL,  CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CCTL,  CWORD,
++    CWORD, CCTL,  CWORD, CCTL,  CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CCTL,  CCTL,  CCTL,      CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,     CWORD, CWORD,
++    CWORD, CWORD, CWORD, CCTL,  CWORD
++} /* clang-format on */;
+ 
+ /* syntax table used when in arithmetic */
+-static const char arisyntax[] = {
+-    CEOF,  CIGN,  CWORD, CCTL,  CCTL,  CCTL,    CCTL,  CCTL,  CCTL,    CCTL,  CCTL,  CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CNL,   CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CVAR,  CWORD, CWORD,
+-    CWORD, CLP,   CRP,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CBACK, CWORD, CWORD, CWORD, CBQUOTE, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD,
+-    CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,   CWORD, CWORD, CENDVAR, CWORD, CWORD,
+-};
++static const char arisyntax[] /* clang-format off */ = {
++    CEOF,    CWORD, CCTL,    CCTL,  CCTL,  CCTL,  CCTL,  CCTL,  CCTL,
++    CCTL,    CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CNL,   CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CVAR,  CWORD, CWORD, CWORD, CLP,   CRP,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CBACK, CWORD, CWORD, CWORD,
++    CBQUOTE, CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CWORD,   CWORD, CWORD, CWORD, CWORD, CWORD, CWORD,
++    CWORD,   CWORD, CENDVAR, CWORD, CWORD
++} /* clang-format on */;
+ 
+ /* character classification table */
+ static const char is_type[] /* clang-format off */ = {
+@@ -1351,19 +1373,19 @@
+     0,       0,       0,       0,       0,       0,       0,       0,
+     0,       0,       0,       0,       0,       0,       0,       0,
+     0,       0,       0,       0,       0,       0,       0,       0,
+-    0,       0,       0,       ISSPECL, 0,       ISSPECL, ISSPECL, 0,
+-    0,       0,       0,       0,       ISSPECL, 0,       0,       ISSPECL,
+-    0,       0,       ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT,
+-    ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT, 0,       0,       0,       0,
+-    0,       ISSPECL, ISSPECL, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER,
++    0,       0,       ISSPECL, 0,       ISSPECL, ISSPECL, 0,       0,
++    0,       0,       0,       ISSPECL, 0,       0,       ISSPECL, 0,
++    0,       ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT,
++    ISDIGIT, ISDIGIT, ISDIGIT, 0,       0,       0,       0,       0,
++    ISSPECL, ISSPECL, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER,
+     ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER,
+     ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER,
+-    ISUPPER, ISUPPER, ISUPPER, ISUPPER, ISUPPER, 0,       0,       0,
+-    0,       ISUNDER, 0,       ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER,
++    ISUPPER, ISUPPER, ISUPPER, ISUPPER, 0,       0,       0,       0,
++    ISUNDER, 0,       ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER,
+     ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER,
+     ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER,
+-    ISLOWER, ISLOWER, ISLOWER, ISLOWER, ISLOWER, 0,       0,       0,
+-    0,       0
++    ISLOWER, ISLOWER, ISLOWER, ISLOWER, 0,       0,       0,       0,
++    0
+ } /* clang-format on */;
+ 
+ static int aliascmd();
+@@ -2141,9 +2163,7 @@
+ static int options(int);
+ static int padvance_magic(const char **, const char *, int);
+ static int patmatch(char *, const char *);
+-static int peektoken(void);
+ static int pgetc(void);
+-static int pgetc2(void);
+ static int pgetc_eatbnl();
+ static int pmatch(const char *, const char *);
+ static int preadbuffer(void);
+@@ -2155,6 +2175,7 @@
+ static int redirectsafe(union node *, int);
+ static int savefd(int, int);
+ static int setinputfile(const char *, int);
++static int sh_open(const char *pathname, int flags, int mayfail);
+ static int showvars(const char *, int, int);
+ static int stoppedjobs(void);
+ static int test_file_access(const char *, int);
+@@ -2195,21 +2216,20 @@
+ static void addcmdentry(char *, struct cmdentry *);
+ static void addfname(char *);
+ static void check_conversion(const char *, const char *);
+-static void clear_traps(void);
+ static void clearcmdentry(void);
+-static void closescript(void);
+ static void defun(union node *);
+ static void delete_cmd_entry(void);
+ static void dotrap(void);
+ static void dupredirect(union node *, int);
+ static void exitreset(void);
+ static void expandarg(union node *arg, struct arglist *arglist, int flag);
+-static void expandmeta(struct strlist *, int);
++static void expandmeta(struct strlist *);
+ static void expbackq(union node *, int);
+ static void expmeta(char *, unsigned, unsigned);
+ static void expredir(union node *);
+ static void find_command(char *, struct cmdentry *, int, const char *);
+ static void fixredir(union node *, const char *, int);
++static void forkreset(void);
+ static void freeparam(volatile struct shparam *);
+ static void hashcd(void);
+ static void ignoresig(int);
+@@ -2222,7 +2242,7 @@
+ static void parseheredoc(void);
+ static void popallfiles(void);
+ static void popfile(void);
+-static void poplocalvars(int);
++static void poplocalvars(void);
+ static void popredir(int);
+ static void popstring(void);
+ static void prehash(union node *);
+@@ -3083,8 +3103,11 @@
+ static int evaltree(union node *n, int flags) {
+   int checkexit = 0;
+   int (*evalfn)(union node *, int);
++  struct stackmark smark;
+   unsigned isor;
+   int status = 0;
++  setstackmark(&smark);
++  if (nflag) goto out;
+   if (n == NULL) {
+     TRACE(("evaltree(NULL) called\n"));
+     goto out;
+@@ -3108,7 +3131,7 @@
+     case NCMD:
+       evalfn = evalcommand;
+     checkexit:
+-      if (eflag && !(flags & EV_TESTED)) checkexit = ~0;
++      checkexit = ~flags & EV_TESTED;
+       goto calleval;
+     case NFOR:
+       evalfn = evalfor;
+@@ -3132,8 +3155,6 @@
+     case NSEMI:
+       isor = n->type - NAND;
+       status = evaltree(n->nbinary.ch1, (flags | ((isor >> 1) - 1)) & EV_TESTED);
+-      /* XXX: -Wlogical-not-parentheses:
+-         if (!status == isor || evalskip) break; */
+       if ((!status) == isor || evalskip) break;
+       n = n->nbinary.ch2;
+     evaln:
+@@ -3160,12 +3181,13 @@
+       break;
+   }
+ out:
+-  if (checkexit & status) goto exexit;
+   dotrap();
++  if (eflag && checkexit & status) goto exexit;
+   if (flags & EV_EXIT) {
+   exexit:
+-    exraise(EXEXIT);
++    exraise(EXEND);
+   }
++  popstackmark(&smark);
+   return exitstatus;
+ }
+ 
+@@ -3261,11 +3283,9 @@
+   struct arglist arglist;
+   union node *argp;
+   struct strlist *sp;
+-  struct stackmark smark;
+   int status;
+   errlinno = lineno = n->nfor.linno;
+   if (funcline) lineno -= funcline - 1;
+-  setstackmark(&smark);
+   arglist.lastp = &arglist.list;
+   for (argp = n->nfor.args; argp; argp = argp->narg.next) {
+     expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
+@@ -3280,7 +3300,6 @@
+     if (skiploop() & ~SKIPCONT) break;
+   }
+   loopnest--;
+-  popstackmark(&smark);
+   return status;
+ }
+ 
+@@ -3304,11 +3323,9 @@
+   union node *cp;
+   union node *patp;
+   struct arglist arglist;
+-  struct stackmark smark;
+   int status = 0;
+   errlinno = lineno = n->ncase.linno;
+   if (funcline) lineno -= funcline - 1;
+-  setstackmark(&smark);
+   arglist.lastp = &arglist.list;
+   expandarg(n->ncase.expr, &arglist, EXP_TILDE);
+   for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) {
+@@ -3326,7 +3343,6 @@
+     }
+   }
+ out:
+-  popstackmark(&smark);
+   return status;
+ }
+ 
+@@ -3340,14 +3356,17 @@
+   errlinno = lineno = n->nredir.linno;
+   if (funcline) lineno -= funcline - 1;
+   expredir(n->nredir.redirect);
+-  if (!backgnd && flags & EV_EXIT && !have_traps()) goto nofork;
+   INTOFF;
++  if (!backgnd && flags & EV_EXIT && !have_traps()) {
++    forkreset();
++    goto nofork;
++  }
+   jp = makejob(n, 1);
+   if (forkshell(jp, n, backgnd) == 0) {
+-    INTON;
+     flags |= EV_EXIT;
+     if (backgnd) flags &= ~EV_TESTED;
+   nofork:
++    INTON;
+     redirect(n->nredir.redirect, 0);
+     evaltreenr(n->nredir.n, flags);
+     /* never returns */
+@@ -3378,7 +3397,7 @@
+       case NFROMFD:
+       case NTOFD:
+         if (redir->ndup.vname) {
+-          expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE);
++          expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR);
+           fixredir(redir, fn.list->text, 1);
+         }
+         break;
+@@ -3527,7 +3546,6 @@
+   struct localvar_list *localvar_stop;
+   struct parsefile *file_stop;
+   struct redirtab *redir_stop;
+-  struct stackmark smark;
+   union node *argp;
+   struct arglist arglist;
+   struct arglist varlist;
+@@ -3550,7 +3568,6 @@
+   if (funcline) lineno -= funcline - 1;
+   /* First expand the arguments. */
+   TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
+-  setstackmark(&smark);
+   file_stop = parsefile;
+   back_exitstatus = 0;
+   cmdentry.cmdtype = CMDBUILTIN;
+@@ -3624,11 +3641,13 @@
+       setvareq((*spp)->text, vflags);
+   }
+   /* Print the command if xflag is set. */
+-  if (xflag) {
++  if (xflag && !inps4) {
+     struct output *out;
+     int sep;
+     out = &preverrout;
++    inps4 = 1;
+     outstr(expandstr(ps4val()), out);
++    inps4 = 0;
+     sep = 0;
+     sep = eprintlist(out, varlist.list, sep);
+     eprintlist(out, osp, sep);
+@@ -3679,7 +3698,6 @@
+      */
+     setvar("_", lastarg, 0);
+   }
+-  popstackmark(&smark);
+   return status;
+ }
+ 
+@@ -3702,6 +3720,7 @@
+   else
+     status = (*cmd->builtin)(argc, argv);
+   flushall();
++  if (out1->flags) sh_warnx("%s: I/O error", commandname);
+   status |= out1->flags;
+   exitstatus = status;
+ cmddone:
+@@ -3893,7 +3912,7 @@
+   exerrno = (e == ELOOP || e == ENAMETOOLONG || e == ENOENT || e == ENOTDIR) ? 127 : 126;
+   exitstatus = exerrno;
+   TRACE(("shellexec failed for %s, errno %d, suppressint %d\n", argv[0], e, suppressint));
+-  exerror(EXEXIT, "%s: %s", argv[0], errmsg(e, E_EXEC));
++  exerror(EXEND, "%s: %s", argv[0], errmsg(e, E_EXEC));
+ }
+ 
+ static void tryexec(char *cmd, char **argv, char **envp) {
+@@ -4498,7 +4517,7 @@
+     ifsbreakup(p, -1, &exparg);
+     *exparg.lastp = NULL;
+     exparg.lastp = &exparg.list;
+-    expandmeta(exparg.list, flag);
++    expandmeta(exparg.list);
+   } else {
+     sp = (struct strlist *)stalloc(sizeof(struct strlist));
+     sp->text = p;
+@@ -4560,7 +4579,7 @@
+       q = stnputs(p, length, expdest);
+       q[-1] &= end - 1;
+       expdest = q - (flag & EXP_WORD ? end : 0);
+-      newloc = expdest - (char *)stackblock() - end;
++      newloc = q - (char *)stackblock() - end;
+       if (breakall && !inquotes && newloc > startloc) {
+         recordregion(startloc, newloc, 0);
+       }
+@@ -4756,7 +4775,7 @@
+   INTON;
+   /* Eat all trailing newlines */
+   dest = expdest;
+-  for (; dest > (char *)stackblock() && dest[-1] == '\n';) {
++  for (; dest > ((char *)stackblock() + startloc) && dest[-1] == '\n';) {
+     STUNPUTC(dest);
+   }
+   expdest = dest;
+@@ -4889,6 +4908,7 @@
+   int patloc;
+   int startloc;
+   long varlen;
++  int discard;
+   int quoted;
+   varflags = *p++;
+   subtype = varflags & VSTYPE;
+@@ -4899,31 +4919,32 @@
+ again:
+   varlen = varvalue(var_, varflags, flag, quoted);
+   if (varflags & VSNUL) varlen--;
++  discard = varlen < 0 ? EXP_DISCARD : 0;
+   switch (subtype) {
+     case VSPLUS:
+-      varlen = -1 - varlen;
++      discard ^= EXP_DISCARD;
+       /* fall through */
+     case 0:
+     case VSMINUS:
+-      p = argstr(p, flag | EXP_TILDE | EXP_WORD);
+-      if (varlen < 0) return p;
++      p = argstr(p, flag | EXP_TILDE | EXP_WORD | (discard ^ EXP_DISCARD));
+       goto record;
+     case VSASSIGN:
+     case VSQUESTION:
+-      if (varlen >= 0) goto record;
+-      p = subevalvar(p, var_, 0, startloc, varflags, flag & ~QUOTES_ESC);
+-      if (flag & EXP_DISCARD) return p;
++      p = subevalvar(p, var_, 0, startloc, varflags, (flag & ~QUOTES_ESC) | (discard ^ EXP_DISCARD));
++      if ((flag | ~discard) & EXP_DISCARD) goto record;
+       varflags &= ~VSNUL;
++      subtype = VSNORMAL;
+       goto again;
+   }
+-  if (varlen < 0 && uflag) varunset(p, var_, 0, 0);
++  if ((discard & ~flag) && uflag) varunset(p, var_, 0, 0);
+   if (subtype == VSLENGTH) {
++    p++;
+     if (flag & EXP_DISCARD) return p;
+     cvtnum(varlen > 0 ? varlen : 0, flag);
+-    goto record;
++    goto really_record;
+   }
+   if (subtype == VSNORMAL) goto record;
+-  flag |= varlen < 0 ? EXP_DISCARD : 0;
++  flag |= discard;
+   if (!(flag & EXP_DISCARD)) {
+     /*
+      * Terminate the string and start recording the pattern
+@@ -4934,7 +4955,8 @@
+   patloc = expdest - (char *)stackblock();
+   p = subevalvar(p, NULL, patloc, startloc, varflags, flag);
+ record:
+-  if (flag & EXP_DISCARD) return p;
++  if ((flag | discard) & EXP_DISCARD) return p;
++really_record:
+   if (quoted) {
+     quoted = *var_ == '@' && shellparam.nparam;
+     if (!quoted) return p;
+@@ -5212,7 +5234,7 @@
+  * Expand shell metacharacters.  At this point, the only control characters
+  * should be escapes.  The results are stored in the list exparg.
+  */
+-static void expandmeta(struct strlist *str, int flag) {
++static void expandmeta(struct strlist *str) {
+   static const char metachars[] = {'*', '?', '[', 0};
+   /* TODO - EXP_REDIR */
+   while (str) {
+@@ -5595,11 +5617,23 @@
+   return memtodest(buf, len, flags);
+ }
+ 
+-/*
+- * Read a character from the script, returning PEOF on end of file.
+- * Nul characters in the input are silently discarded.
+- */
+-static int pgetc(void) {
++static void freestrings(struct strpush *sp) {
++  INTOFF;
++  do {
++    struct strpush *psp;
++    if (sp->ap) {
++      sp->ap->flag &= ~ALIASINUSE;
++      if (sp->ap->flag & ALIASDEAD) unalias(sp->ap->name);
++    }
++    psp = sp;
++    sp = sp->spfree;
++    if (psp != &(parsefile->basestrpush)) ckfree(psp);
++  } while (sp);
++  parsefile->spfree = NULL;
++  INTON;
++}
++
++static int pgetc_nofree(void) {
+   int c;
+   if (parsefile->unget) return parsefile->lastc[--parsefile->unget];
+   if (--parsefile->nleft >= 0)
+@@ -5612,14 +5646,13 @@
+ }
+ 
+ /*
+- * Same as pgetc(), but ignores PEOA.
++ * Read a character from the script, returning PEOF on end of file.
++ * Nul characters in the input are silently discarded.
+  */
+-static int pgetc2() {
+-  int c;
+-  do {
+-    c = pgetc();
+-  } while (c == PEOA);
+-  return c;
++int pgetc(void) {
++  struct strpush *sp = parsefile->spfree;
++  if (unlikely(sp)) freestrings(sp);
++  return pgetc_nofree();
+ }
+ 
+ static void AddUniqueCompletion(linenoiseCompletions *c, char *s) {
+@@ -5774,12 +5807,8 @@
+   int more;
+   char savec;
+   if (unlikely(parsefile->strpush)) {
+-    if (parsefile->nleft == -1 && parsefile->strpush->ap && parsefile->nextc[-1] != ' ' &&
+-        parsefile->nextc[-1] != '\t') {
+-      return PEOA;
+-    }
+     popstring();
+-    return pgetc();
++    return pgetc_nofree();
+   }
+   if (unlikely(parsefile->nleft == EOF_NLEFT || parsefile->buf == NULL)) return PEOF;
+   flushall();
+@@ -5840,7 +5869,7 @@
+   len = strlen(s);
+   INTOFF;
+   /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
+-  if (parsefile->strpush) {
++  if ((unsigned long)parsefile->strpush | (unsigned long)parsefile->spfree) {
+     sp = ckmalloc(sizeof(struct strpush));
+     sp->prev = parsefile->strpush;
+     parsefile->strpush = sp;
+@@ -5849,6 +5878,7 @@
+   sp->prevstring = parsefile->nextc;
+   sp->prevnleft = parsefile->nleft;
+   sp->unget = parsefile->unget;
++  sp->spfree = parsefile->spfree;
+   memcpy(sp->lastc, parsefile->lastc, sizeof(sp->lastc));
+   sp->ap = (struct alias *)ap;
+   if (ap) {
+@@ -5858,6 +5888,7 @@
+   parsefile->nextc = s;
+   parsefile->nleft = len;
+   parsefile->unget = 0;
++  parsefile->spfree = NULL;
+   INTON;
+ }
+ 
+@@ -5871,10 +5902,6 @@
+     if (sp->string != sp->ap->val) {
+       ckfree(sp->string);
+     }
+-    sp->ap->flag &= ~ALIASINUSE;
+-    if (sp->ap->flag & ALIASDEAD) {
+-      unalias(sp->ap->name);
+-    }
+   }
+   parsefile->nextc = sp->prevstring;
+   parsefile->nleft = sp->prevnleft;
+@@ -5882,7 +5909,7 @@
+   memcpy(parsefile->lastc, sp->lastc, sizeof(sp->lastc));
+   /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
+   parsefile->strpush = sp->prev;
+-  if (sp != &(parsefile->basestrpush)) ckfree(sp);
++  parsefile->spfree = sp;
+   INTON;
+ }
+ 
+@@ -5893,11 +5920,8 @@
+ static int setinputfile(const char *fname, int flags) {
+   int fd;
+   INTOFF;
+-  if ((fd = open(fname, O_RDONLY, 0)) < 0) {
+-    if (flags & INPUT_NOFILE_OK) goto out;
+-    exitstatus = 127;
+-    exerror(EXERROR, "Can't open %s", fname);
+-  }
++  fd = sh_open(fname, O_RDONLY, flags & INPUT_NOFILE_OK);
++  if (fd < 0) goto out;
+   if (fd < 10) fd = savefd(fd, fd);
+   setinputfd(fd, flags & INPUT_PUSH_FILE);
+ out:
+@@ -5943,6 +5967,7 @@
+   pf->prev = parsefile;
+   pf->fd = -1;
+   pf->strpush = NULL;
++  pf->spfree = NULL;
+   pf->basestrpush.prev = NULL;
+   pf->unget = 0;
+   parsefile = pf;
+@@ -5953,7 +5978,11 @@
+   INTOFF;
+   if (pf->fd >= 0) close(pf->fd);
+   if (pf->buf) ckfree(pf->buf);
+-  while (pf->strpush) popstring();
++  if (parsefile->spfree) freestrings(parsefile->spfree);
++  while (pf->strpush) {
++    popstring();
++    freestrings(parsefile->spfree);
++  }
+   parsefile = pf->prev;
+   ckfree(pf);
+   INTON;
+@@ -5970,18 +5999,6 @@
+   unwindfiles(&basepf);
+ }
+ 
+-/*
+- * Close the file(s) that the shell is reading commands from.  Called
+- * after a fork is done.
+- */
+-static void closescript(void) {
+-  popallfiles();
+-  if (parsefile->fd > 0) {
+-    close(parsefile->fd);
+-    parsefile->fd = 0;
+-  }
+-}
+-
+ static char *commandtext(union node *);
+ static int dowait(int, struct job *);
+ static int getstatus(struct job *);
+@@ -6052,7 +6069,7 @@
+   if (on == jobctl || rootshell == 0) return;
+   if (on) {
+     int ofd;
+-    ofd = fd = open(_PATH_TTY, O_RDWR, 0);
++    ofd = fd = sh_open(_PATH_TTY, O_RDWR, 1);
+     if (fd < 0) {
+       fd += 3;
+       while (!isatty(fd))
+@@ -6322,8 +6339,8 @@
+ static void showjobs(struct output *out, int mode) {
+   struct job *jp;
+   TRACE(("showjobs(%x) called\n", mode));
+-  /* If not even one one job changed, there is nothing to do */
+-  dowait(DOWAIT_NORMAL, NULL);
++  /* If not even one job changed, there is nothing to do */
++  dowait(DOWAIT_NONBLOCK, NULL);
+   for (jp = curjob; jp; jp = jp->prev_job) {
+     if (!(mode & SHOW_CHANGED) || jp->changed) showjob(out, jp, mode);
+   }
+@@ -6365,7 +6382,7 @@
+         jp->waited = 1;
+         jp = jp->prev_job;
+       }
+-      if (!dowait(DOWAIT_WAITCMD, 0)) goto sigout;
++      if (!dowait(DOWAIT_WAITCMD_ALL, 0)) goto sigout;
+     }
+   }
+   retval = 127;
+@@ -6546,8 +6563,7 @@
+   lvforked = vforked;
+   if (!lvforked) {
+     shlvl++;
+-    closescript();
+-    clear_traps();
++    forkreset();
+     /* do job control only in root shell */
+     jobctl = 0;
+   }
+@@ -6567,14 +6583,12 @@
+     ignoresig(SIGQUIT);
+     if (jp->nprocs == 0) {
+       close(0);
+-      if (open(_PATH_DEVNULL, O_RDONLY, 0) != 0) sh_error("Can't open %s", _PATH_DEVNULL);
++      sh_open(_PATH_DEVNULL, O_RDONLY, 0);
+     }
+   }
+   if (!oldlvl && iflag) {
+-    if (mode != FORK_BG) {
+-      setsignal(SIGINT);
+-      setsignal(SIGQUIT);
+-    }
++    setsignal(SIGINT);
++    setsignal(SIGQUIT);
+     setsignal(SIGTERM);
+   }
+   if (lvforked) return;
+@@ -6666,7 +6680,7 @@
+ static int waitforjob(struct job *jp) {
+   int st;
+   TRACE(("waitforjob(%%%d) called\n", jp ? jobno(jp) : 0));
+-  dowait(jp ? DOWAIT_BLOCK : DOWAIT_NORMAL, jp);
++  dowait(jp ? DOWAIT_BLOCK : DOWAIT_NONBLOCK, jp);
+   if (!jp) return exitstatus;
+   st = getstatus(jp);
+   if (jp->jobctl) {
+@@ -6750,12 +6764,19 @@
+ }
+ 
+ static int dowait(int block, struct job *jp) {
+-  int pid = block == DOWAIT_NORMAL ? gotsigchld : 1;
+-  while (jp ? jp->state == JOBRUNNING : pid > 0) {
+-    if (!jp) gotsigchld = 0;
++  int gotchld = *(volatile int *)&gotsigchld;
++  int rpid;
++  int pid;
++  if (jp && jp->state != JOBRUNNING) block = DOWAIT_NONBLOCK;
++  if (block == DOWAIT_NONBLOCK && !gotchld) return 1;
++  rpid = 1;
++  do {
+     pid = waitone(block, jp);
+-  }
+-  return pid;
++    rpid &= !!pid;
++    block &= ~DOWAIT_WAITCMD_ALL;
++    if (!pid || (jp && jp->state != JOBRUNNING)) block = DOWAIT_NONBLOCK;
++  } while (pid >= 0);
++  return rpid;
+ }
+ 
+ /*
+@@ -6778,12 +6799,13 @@
+   int err;
+   if (jobctl) flags |= WUNTRACED;
+   do {
+-    err = wait3(status, flags, NULL);
++    gotsigchld = 0;
++    do err = wait3(status, flags, NULL);
++    while (err < 0 && errno == EINTR);
+     if (err || (err = -!block)) break;
+     sigblockall(&oldmask);
+     while (!gotsigchld && !pending_sig) sigsuspend(&oldmask);
+     sigclearmask();
+-    err = 0;
+   } while (gotsigchld);
+   return err;
+ }
+@@ -7062,7 +7084,11 @@
+ }
+ 
+ static void xtcsetpgrp(int fd, int pgrp) {
+-  if (tcsetpgrp(fd, pgrp)) sh_error("Cannot set tty process group (%s)", strerror(errno));
++  int err;
++  sigblockall(NULL);
++  err = tcsetpgrp(fd, pgrp);
++  sigclearmask();
++  if (err) sh_error("Cannot set tty process group (%s)", strerror(errno));
+ }
+ 
+ static int getstatus(struct job *job) {
+@@ -7458,7 +7484,6 @@
+     setinputfile(*xargv, 0);
+   setarg0:
+     arg0 = *xargv++;
+-    commandname = arg0;
+   }
+   shellparam.p = xargv;
+   shellparam.optind = 1;
+@@ -7803,22 +7828,27 @@
+ }
+ 
+ static union node *list(int nlflag) {
++  int chknl = nlflag & 1 ? 0 : CHKNL;
+   union node *n1, *n2, *n3;
+   int tok;
+   n1 = NULL;
+   for (;;) {
+-    switch (peektoken()) {
++    checkkwd = chknl | CHKKWD | CHKALIAS;
++    tok = readtoken();
++    switch (tok) {
+       case TNL:
+-        if (!(nlflag & 1)) break;
+         parseheredoc();
+         return n1;
+       case TEOF:
+-        if (!n1 && (nlflag & 1)) n1 = NEOF;
++        if (!n1 && !chknl) n1 = NEOF;
++      out_eof:
+         parseheredoc();
++        tokpushback++;
++        lasttoken = TEOF;
+         return n1;
+     }
+-    checkkwd = CHKNL | CHKKWD | CHKALIAS;
+-    if (nlflag == 2 && tokendlist[peektoken()]) return n1;
++    tokpushback++;
++    if (nlflag == 2 && tokendlist[tok]) return n1;
+     nlflag |= 2;
+     n2 = andor();
+     tok = readtoken();
+@@ -7845,15 +7875,16 @@
+       n1 = n3;
+     }
+     switch (tok) {
+-      case TNL:
+       case TEOF:
++        goto out_eof;
++      case TNL:
+         tokpushback++;
+         /* fall through */
+       case TBACKGND:
+       case TSEMI:
+         break;
+       default:
+-        if ((nlflag & 1)) synexpect(-1);
++        if (!chknl) synexpect(-1);
+         tokpushback++;
+         return n1;
+     }
+@@ -8248,13 +8279,6 @@
+   }
+ }
+ 
+-static int peektoken(void) {
+-  int t;
+-  t = readtoken();
+-  tokpushback++;
+-  return (t);
+-}
+-
+ static int readtoken(void) {
+   int t;
+   int kwd = checkkwd;
+@@ -8266,9 +8290,12 @@
+   if (kwd & CHKNL) {
+     while (t == TNL) {
+       parseheredoc();
++      checkkwd = 0;
+       t = xxreadtoken();
+     }
+   }
++  kwd |= checkkwd;
++  checkkwd = 0;
+   if (t != TWORD || quoteflag) {
+     goto out;
+   }
+@@ -8284,7 +8311,7 @@
+       goto out;
+     }
+   }
+-  if (checkkwd & CHKALIAS) {
++  if (kwd & CHKALIAS) {
+     struct alias *ap;
+     if ((ap = lookupalias(wordtext, 1)) != NULL) {
+       if (*ap->val) {
+@@ -8294,7 +8321,6 @@
+     }
+   }
+ out:
+-  checkkwd = 0;
+   return (t);
+ }
+ 
+@@ -8338,7 +8364,6 @@
+     switch (c) {
+       case ' ':
+       case '\t':
+-      case PEOA:
+         continue;
+       case '#':
+         while ((c = pgetc()) != '\n' && c != PEOF)
+@@ -8376,7 +8401,7 @@
+ static int pgetc_eatbnl(void) {
+   int c;
+   while ((c = pgetc()) == '\\') {
+-    if (pgetc2() != '\n') {
++    if (pgetc() != '\n') {
+       pungetc();
+       break;
+     }
+@@ -8481,7 +8506,7 @@
+         break;
+       /* backslash */
+       case CBACK:
+-        c = pgetc2();
++        c = pgetc();
+         if (c == PEOF) {
+           USTPUTC(CTLESC, out);
+           USTPUTC('\\', out);
+@@ -8568,13 +8593,9 @@
+         break;
+       case CEOF:
+         goto endword; /* exit outer loop */
+-      case CIGN:
+-        break;
+       default:
+         if (synstack->varnest == 0) goto endword; /* exit outer loop */
+-        if (c != PEOA) {
+-          USTPUTC(c, out);
+-        }
++        USTPUTC(c, out);
+     }
+     c = pgetc_top(synstack);
+   }
+@@ -8613,18 +8634,13 @@
+   if (realeofmark(eofmark)) {
+     int markloc;
+     char *p;
+-    if (c == PEOA) {
+-      c = pgetc2();
+-    }
+     if (striptabs) {
+-      while (c == '\t') {
+-        c = pgetc2();
+-      }
++      while (c == '\t') c = pgetc();
+     }
+     markloc = out - (char *)stackblock();
+     for (p = eofmark; STPUTC(c, out), *p; p++) {
+       if (c != *p) goto more_heredoc;
+-      c = pgetc2();
++      c = pgetc();
+     }
+     if (c == '\n' || c == PEOF) {
+       c = PEOF;
+@@ -8717,8 +8733,7 @@
+   char *p;
+   static const char types[] = "}-+?=";
+   c = pgetc_eatbnl();
+-  if ((checkkwd & CHKEOFMARK) || c <= PEOA ||
+-      (c != '(' && c != '{' && !is_name(c) && !is_special(c))) {
++  if ((checkkwd & CHKEOFMARK) || (c != '(' && c != '{' && !is_name(c) && !is_special(c))) {
+     USTPUTC('$', out);
+     pungetc();
+   } else if (c == '(') { /* $(command) or $((arith)) */
+@@ -8748,7 +8763,7 @@
+       do {
+         STPUTC(c, out);
+         c = pgetc_eatbnl();
+-      } while (is_digit(c));
++      } while ((subtype <= 0 || subtype >= VSLENGTH) && is_digit(c));
+     } else if (c != '}') {
+       int cc = c;
+       c = pgetc_eatbnl();
+@@ -8795,6 +8810,7 @@
+           break;
+       }
+     } else {
++      if (subtype == VSLENGTH && c != '}') subtype = 0;
+     badsub:
+       pungetc();
+     }
+@@ -8850,15 +8866,11 @@
+         case '`':
+           goto done;
+         case '\\':
+-          pc = pgetc_eatbnl();
++          pc = pgetc();
+           if (pc != '\\' && pc != '`' && pc != '$' && (!synstack->dblquote || pc != '"'))
+             STPUTC('\\', pout);
+-          if (pc > PEOA) {
+-            break;
+-          }
+-          /* fall through */
++          break;
+         case PEOF:
+-        case PEOA:
+           synerror("EOF in backquote substitution");
+         case '\n':
+           nlnoprompt();
+@@ -8892,8 +8904,8 @@
+   else {
+     if (readtoken() != TRP) synexpect(TRP);
+     setinputstring(nullstr);
+-    parseheredoc();
+   }
++  parseheredoc();
+   heredoclist = saveheredoclist;
+   (*nlpp)->n = n;
+   /* Start reading from old file again. */
+@@ -8938,21 +8950,38 @@
+ }
+ 
+ static const char *expandstr(const char *ps) {
+-  union node n;
++  struct parsefile *file_stop;
++  struct jmploc *volatile savehandler;
++  struct heredoc *saveheredoclist;
++  const char *result;
+   int saveprompt;
+-  /* XXX Fix (char *) cast. */
+-  setinputstring((char *)ps);
++  struct jmploc jmploc;
++  union node n;
++  int err;
++  file_stop = parsefile;
++  setinputstring((char *)ps); /* XXX Fix (char *) cast. */
++  saveheredoclist = heredoclist;
++  heredoclist = NULL;
+   saveprompt = doprompt;
+   doprompt = 0;
++  result = ps;
++  savehandler = handler;
++  if (unlikely(err = setjmp(jmploc.loc))) goto out;
++  handler = &jmploc;
+   readtoken1(pgetc_eatbnl(), DQSYNTAX, FAKEEOFMARK, 0);
+-  doprompt = saveprompt;
+-  popfile();
+   n.narg.type = NARG;
+   n.narg.next = NULL;
+   n.narg.text = wordtext;
+   n.narg.backquote = backquotelist;
+   expandarg(&n, NULL, EXP_QUOTED);
+-  return stackblock();
++  result = stackblock();
++out:
++  handler = savehandler;
++  if (err && exception != EXERROR) longjmp(handler->loc, 1);
++  doprompt = saveprompt;
++  unwindfiles(file_stop);
++  heredoclist = saveheredoclist;
++  return result;
+ }
+ 
+ /*
+@@ -8979,6 +9008,16 @@
+   return findstring(s, parsekwd, sizeof(parsekwd) / sizeof(const char *));
+ }
+ 
++static unsigned update_closed_redirs(int fd, int nfd) {
++  unsigned val = closed_redirs;
++  unsigned bit = 1 << fd;
++  if (nfd >= 0)
++    closed_redirs &= ~bit;
++  else
++    closed_redirs |= bit;
++  return val & bit;
++}
++
+ /*
+  * Process a list of redirection commands.  If the REDIR_PUSH flag is set,
+  * old file descriptors are stashed away so that the redirection can be
+@@ -9003,17 +9042,17 @@
+     if (newfd < -1) continue;
+     fd = n->nfile.fd;
+     if (sv) {
++      int closed;
+       p = &sv->renamed[fd];
+       i = *p;
++      closed = update_closed_redirs(fd, newfd);
+       if (likely(i == EMPTY)) {
+         i = CLOSED;
+-        if (fd != newfd) {
++        if (fd != newfd && !closed) {
+           i = savefd(fd, fd);
+           fd = -1;
+         }
+       }
+-      if (i == newfd) /* Can only happen if i == newfd == CLOSED */
+-        i = REALLY_CLOSED;
+       *p = i;
+     }
+     if (fd == newfd) continue;
+@@ -9023,47 +9062,66 @@
+   if (flags & REDIR_SAVEFD2 && sv->renamed[2] >= 0) preverrout.fd = sv->renamed[2];
+ }
+ 
++wontreturn static int sh_open_fail(const char *pathname, int flags, int e) {
++  const char *word;
++  int action;
++  word = "open";
++  action = E_OPEN;
++  if (flags & O_CREAT) {
++    word = "create";
++    action = E_CREAT;
++  }
++  sh_error("cannot %s %s: %s", word, pathname, errmsg(e, action));
++}
++
++static int sh_open(const char *pathname, int flags, int mayfail) {
++  int fd;
++  int e;
++  do {
++    fd = open(pathname, flags, 0666);
++    e = errno;
++  } while (fd < 0 && e == EINTR && !pending_sig);
++  if (mayfail || fd >= 0) return fd;
++  sh_open_fail(pathname, flags, e);
++}
++
+ static int openredirect(union node *redir) {
+   struct stat sb;
+   char *fname;
++  int flags;
+   int f;
+   switch (redir->nfile.type) {
+     case NFROM:
+-      fname = redir->nfile.expfname;
+-      if ((f = open(fname, O_RDONLY, 0)) < 0) goto eopen;
++      flags = O_RDONLY;
++    do_open:
++      f = sh_open(redir->nfile.expfname, flags, 0);
+       break;
+     case NFROMTO:
+-      fname = redir->nfile.expfname;
+-      if ((f = open(fname, O_RDWR | O_CREAT, 0666)) < 0) goto ecreate;
+-      break;
++      flags = O_RDWR|O_CREAT;
++      goto do_open;
+     case NTO:
+       /* Take care of noclobber mode. */
+       if (Cflag) {
+         fname = redir->nfile.expfname;
+         if (stat(fname, &sb) < 0) {
+-          if ((f = open(fname, O_WRONLY | O_CREAT | O_EXCL, 0666)) < 0) goto ecreate;
+-        } else if (!S_ISREG(sb.st_mode)) {
+-          if ((f = open(fname, O_WRONLY, 0666)) < 0) goto ecreate;
+-          if (!fstat(f, &sb) && S_ISREG(sb.st_mode)) {
+-            close(f);
+-            errno = EEXIST;
+-            goto ecreate;
+-          }
+-        } else {
+-          errno = EEXIST;
++          flags = O_WRONLY|O_CREAT|O_EXCL;
++          goto do_open;
++        }
++        if (S_ISREG(sb.st_mode)) goto ecreate;
++        f = sh_open(fname, O_WRONLY, 0);
++        if (!fstat(f, &sb) && S_ISREG(sb.st_mode)) {
++          close(f);
+           goto ecreate;
+         }
+         break;
+       }
+       /* FALLTHROUGH */
+     case NCLOBBER:
+-      fname = redir->nfile.expfname;
+-      if ((f = open(fname, O_WRONLY | O_CREAT | O_TRUNC, 0666)) < 0) goto ecreate;
+-      break;
++      flags = O_WRONLY|O_CREAT|O_TRUNC;
++      goto do_open;
+     case NAPPEND:
+-      fname = redir->nfile.expfname;
+-      if ((f = open(fname, O_WRONLY | O_CREAT | O_APPEND, 0666)) < 0) goto ecreate;
+-      break;
++      flags = O_WRONLY|O_CREAT|O_APPEND;
++      goto do_open;
+     case NTOFD:
+     case NFROMFD:
+       f = redir->ndup.dupfd;
+@@ -9078,9 +9136,7 @@
+   }
+   return f;
+ ecreate:
+-  sh_error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
+-eopen:
+-  sh_error("cannot open %s: %s", fname, errmsg(errno, E_OPEN));
++  sh_open_fail(fname, O_CREAT, EEXIST);
+ }
+ 
+ static void dupredirect(union node *redir, int f) {
+@@ -9148,13 +9204,13 @@
+   int i;
+   INTOFF;
+   rp = redirlist;
+-  for (i = 0; i < 10; i++) {
++  for (i = 0 ; i < 10 ; i++) {
++    int closed;
++    if (rp->renamed[i] == EMPTY) continue;
++    closed = drop ? 1 : update_closed_redirs(i, rp->renamed[i]);
+     switch (rp->renamed[i]) {
+       case CLOSED:
+-        if (!drop) close(i);
+-        break;
+-      case EMPTY:
+-      case REALLY_CLOSED:
++        if (!closed) close(i);
+         break;
+       default:
+         if (!drop) dup2(rp->renamed[i], i);
+@@ -9268,23 +9324,6 @@
+   return 0;
+ }
+ 
+-/*
+- * Clear traps on a fork.
+- */
+-static void clear_traps(void) {
+-  char **tp;
+-  INTOFF;
+-  for (tp = trap; tp < &trap[NSIG]; tp++) {
+-    if (*tp && **tp) { /* trap not NULL or SIG_IGN */
+-      ckfree(*tp);
+-      *tp = NULL;
+-      if (tp != &trap[0]) setsignal(tp - trap);
+-    }
+-  }
+-  trapcnt = 0;
+-  INTON;
+-}
+-
+ /*
+  * Set the signal handler for the specified signal.  The routine figures
+  * out what it should be set to.
+@@ -9437,15 +9476,17 @@
+     trap[0] = NULL;
+     evalskip = 0;
+     evalstring(p, 0);
++    evalskip = SKIPFUNCDEF;
+   }
+ out:
++  exitreset();
+   /*
+    * Disable job control so that whoever had the foreground before we
+    * started can get it back.
+    */
+   if (likely(!setjmp(loc.loc))) setjobctl(0);
+   flushall();
+-  _exit(savestatus);
++  _exit(exitstatus);
+ }
+ 
+ static int decode_signal(const char *string, int minsig) {
+@@ -10104,12 +10145,23 @@
+ static int timescmd() {
+   struct tms buf;
+   long int clk_tck = sysconf(_SC_CLK_TCK);
++  int mutime, mstime, mcutime, mcstime;
++  double utime, stime, cutime, cstime;
+   times(&buf);
+-  Printf("%dm%fs %dm%fs\n%dm%fs %dm%fs\n", (int)(buf.tms_utime / clk_tck / 60),
+-         ((double)buf.tms_utime) / clk_tck, (int)(buf.tms_stime / clk_tck / 60),
+-         ((double)buf.tms_stime) / clk_tck, (int)(buf.tms_cutime / clk_tck / 60),
+-         ((double)buf.tms_cutime) / clk_tck, (int)(buf.tms_cstime / clk_tck / 60),
+-         ((double)buf.tms_cstime) / clk_tck);
++  utime = (double)buf.tms_utime / clk_tck;
++  mutime = utime / 60;
++  utime -= mutime * 60.0;
++  stime = (double)buf.tms_stime / clk_tck;
++  mstime = stime / 60;
++  stime -= mstime * 60.0;
++  cutime = (double)buf.tms_cutime / clk_tck;
++  mcutime = cutime / 60;
++  cutime -= mcutime * 60.0;
++  cstime = (double)buf.tms_cstime / clk_tck;
++  mcstime = cstime / 60;
++  cstime -= mcstime * 60.0;
++  Printf("%dm%fs %dm%fs\n%dm%fs %dm%fs\n", mutime, utime, mstime, stime,
++         mcutime, cutime, mcstime, cstime);
+   return 0;
+ }
+ 
+@@ -10402,7 +10454,7 @@
+  * Called after a function returns.
+  * Interrupts must be off.
+  */
+-static void poplocalvars(int keep) {
++static void poplocalvars(void) {
+   struct localvar_list *ll;
+   struct localvar *lvp, *next;
+   struct Var *vp;
+@@ -10415,18 +10467,7 @@
+     next = lvp->next;
+     vp = lvp->vp;
+     TRACE(("poplocalvar %s\n", vp ? vp->text : "-"));
+-    if (keep) {
+-      int bits = VSTRFIXED;
+-      if (lvp->flags != VUNSET) {
+-        if (vp->text == lvp->text)
+-          bits |= VTEXTFIXED;
+-        else if (!(lvp->flags & (VTEXTFIXED | VSTACK)))
+-          ckfree(lvp->text);
+-      }
+-      vp->flags &= ~bits;
+-      vp->flags |= (lvp->flags & bits);
+-      if ((vp->flags & (VEXPORT | VREADONLY | VSTRFIXED | VUNSET)) == VUNSET) unsetvar(vp->text);
+-    } else if (vp == NULL) { /* $- saved */
++    if (vp == NULL) { /* $- saved */
+       memcpy(optlist, lvp->text, sizeof(optlist));
+       ckfree(lvp->text);
+       optschanged();
+@@ -10463,7 +10504,7 @@
+ }
+ 
+ static void unwindlocalvars(struct localvar_list *stop) {
+-  while (localvar_stack != stop) poplocalvars(0);
++  while (localvar_stack != stop) poplocalvars();
+ }
+ 
+ /*
+@@ -10506,8 +10547,7 @@
+     sigmode[SIGCHLD - 1] = S_DFL;
+     setsignal(SIGCHLD);
+   }
+-  /* from output.c: */
+-  {} /* from var.c: */
++  /* from var.c: */
+   {
+     char **envp;
+     static char ppid[32] = "PPID=";
+@@ -10543,12 +10583,14 @@
+ static void exitreset() {
+   /* from eval.c: */
+   {
+-    evalskip = 0;
+-    loopnest = 0;
+     if (savestatus >= 0) {
+-      exitstatus = savestatus;
++      if (exception == EXEXIT || evalskip == SKIPFUNCDEF)
++        exitstatus = savestatus;
+       savestatus = -1;
+     }
++    evalskip = 0;
++    loopnest = 0;
++    inps4 = 0;
+   }
+   /* from expand.c: */
+   { ifsfree(); }
+@@ -10561,6 +10603,43 @@
+   }
+ }
+ 
++/*
++ * This routine is called when we enter a subshell.
++ */
++static void forkreset() {
++  /* from input.c: */
++  {
++    popallfiles();
++    if (parsefile->fd > 0) {
++      close(parsefile->fd);
++      parsefile->fd = 0;
++    }
++  }
++  /* from main.c: */
++  {
++    handler = &main_handler;
++  }
++  /* from redir.c: */
++  {
++    redirlist = NULL;
++  }
++  /* from trap.c: */
++  {
++    char **tp;
++    INTOFF;
++    for (tp = trap ; tp < &trap[NSIG] ; tp++) {
++      if (*tp && **tp) {  /* trap not NULL or SIG_IGN */
++        ckfree(*tp);
++        *tp = NULL;
++        if (tp != &trap[0])
++        setsignal(tp - trap);
++      }
++    }
++    trapcnt = 0;
++    INTON;
++  }
++}
++
+ /*
+  * This routine is called when an error or an interrupt occurs in an
+  * interactive shell and control is returned to the main command loop.
+@@ -10570,10 +10649,10 @@
+   {
+     /* clear input buffer */
+     basepf.lleft = basepf.nleft = 0;
++    basepf.unget = 0;
+     popallfiles();
+   }
+-  /* from output.c: */
+-  {} /* from var.c: */
++  /* from var.c: */
+   {
+     unwindlocalvars(0);
+   }
+@@ -10815,11 +10894,17 @@
+     if (n == NEOF) {
+       if (!top || numeof >= 50) break;
+       if (!stoppedjobs()) {
+-        if (!Iflag) break;
++        if (!Iflag) {
++          if (iflag) {
++            outcslow('\n', out2);
++            flushout(out2);
++          }
++          break;
++        }
+         outstr("\nUse \"exit\" to leave shell.\n", out2);
+       }
+       numeof++;
+-    } else if (nflag == 0) {
++    } else {
+       int i;
+       job_warning = (job_warning == 2) ? 1 : 0;
+       numeof = 0;
+@@ -10899,17 +10984,16 @@
+ int main(int argc, char **argv) {
+   char *shinit;
+   volatile int state;
+-  struct jmploc jmploc;
+   struct stackmark smark;
+   int login;
+   state = 0;
+-  if (unlikely(setjmp(jmploc.loc))) {
++  if (unlikely(setjmp(main_handler.loc))) {
+     int e;
+     int s;
+     exitreset();
+     e = exception;
+     s = state;
+-    if (e == EXEXIT || s == 0 || iflag == 0 || shlvl) exitshell();
++    if (e == EXEND || e == EXEXIT || s == 0 || iflag == 0 || shlvl) exitshell();
+     reset();
+     if (e == EXINT) {
+       outcslow('\n', out2);
+@@ -10926,7 +11010,7 @@
+       goto state4;
+     }
+   }
+-  handler = &jmploc;
++  handler = &main_handler;
+   rootpid = getpid();
+   init();
+   setstackmark(&smark);