[bug#57050] [PATCH v4 06/14] gnu: chez-scheme: Fix use of "/bin/sh".

[Philip McGrath <philip@philipmcgrath.com>]

The unsuccessful attempt to execute "/bin/sh" by Chez Scheme's 'process'
function seems to have caused parts of the Chez Scheme test suite to
have been silently skipped. The issue was exposed by the upcoming
changes to Racket's build system.

* gnu/packages/patches/chez-scheme-bin-sh.patch,
gnu/packages/patches/racket-chez-scheme-bin-sh.patch: New patches.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/racket.scm (%racket-origin)[patches]: Update accordingly.
* gnu/packages/chez.scm (chez-scheme)[origin]<patches>: Likewise.
---
 gnu/local.mk                                  |  2 +
 gnu/packages/chez.scm                         |  1 +
 gnu/packages/patches/chez-scheme-bin-sh.patch | 76 +++++++++++++++++++
 .../patches/racket-chez-scheme-bin-sh.patch   | 76 +++++++++++++++++++
 gnu/packages/racket.scm                       |  3 +-
 5 files changed, 157 insertions(+), 1 deletion(-)
 create mode 100644 gnu/packages/patches/chez-scheme-bin-sh.patch
 create mode 100644 gnu/packages/patches/racket-chez-scheme-bin-sh.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index fae32a11e5..babd54c8c6 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -941,6 +941,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/ceph-boost-compat.patch			\
   %D%/packages/patches/ceph-rocksdb-compat.patch		\
   %D%/packages/patches/cheese-vala-update.patch		        \
+  %D%/packages/patches/chez-scheme-bin-sh.patch			\
   %D%/packages/patches/chmlib-inttypes.patch			\
   %D%/packages/patches/cl-asdf-config-directories.patch		\
   %D%/packages/patches/clamav-config-llvm-libs.patch		\
@@ -1768,6 +1769,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/ripperx-missing-file.patch		\
   %D%/packages/patches/rpcbind-CVE-2017-8779.patch		\
   %D%/packages/patches/rtags-separate-rct.patch			\
+  %D%/packages/patches/racket-chez-scheme-bin-sh.patch		\
   %D%/packages/patches/racket-rktio-bin-sh.patch		\
   %D%/packages/patches/remake-impure-dirs.patch			\
   %D%/packages/patches/restic-0.9.6-fix-tests-for-go1.15.patch	\
diff --git a/gnu/packages/chez.scm b/gnu/packages/chez.scm
index 812d41fc5b..c627c4d842 100644
--- a/gnu/packages/chez.scm
+++ b/gnu/packages/chez.scm
@@ -269,6 +269,7 @@ (define-public chez-scheme
                (base32
                 "0xchqq8cm0ka5wgpn18sjs0hh15rc3nb7xrjqbbc9al3asq0d7gc"))
               (file-name (git-file-name name version))
+              (patches (search-patches "chez-scheme-bin-sh.patch"))
               (snippet #~(begin
                            (use-modules (guix build utils))
                            ;; TODO: consider putting this in a (guix ...) or
diff --git a/gnu/packages/patches/chez-scheme-bin-sh.patch b/gnu/packages/patches/chez-scheme-bin-sh.patch
new file mode 100644
index 0000000000..7650914f01
--- /dev/null
+++ b/gnu/packages/patches/chez-scheme-bin-sh.patch
@@ -0,0 +1,76 @@
+From 3c838e6a0c3214d95bf02048cddccfd1b69a679f Mon Sep 17 00:00:00 2001
+From: Philip McGrath <philip@philipmcgrath.com>
+Date: Thu, 19 May 2022 13:41:56 -0400
+Subject: [PATCH] patch s_process for "/bin/sh" on Guix
+
+If:
+
+    1. The nonstandard but ubiquitous macro `_PATH_BSHELL` from
+       <paths.h> is defined; and
+
+    2. The path specified by `_PATH_BSHELL` exists;
+
+then `s_process` will call `execl` with the file specified by
+`_PATH_BSHELL` instead of "/bin/sh".
+
+Checking that the path specified by `_PATH_BSHELL` exists safeguards
+against obscure errors if attempting to use stand-alone executables
+built by the patched Racket in non-Guix envoronments.
+
+This patch does not change the behavior of `s_system`, which relies
+on `system` from the C library.
+---
+ c/prim5.c | 21 ++++++++++++++++++++-
+ 1 file changed, 20 insertions(+), 1 deletion(-)
+
+diff --git a/c/prim5.c b/c/prim5.c
+index 5a07893..bc2736c 100644
+--- a/c/prim5.c
++++ b/c/prim5.c
+@@ -23,6 +23,12 @@
+ #include <ctype.h>
+ #include <math.h>
+ 
++/* BEGIN PATCH for Guix */
++#ifndef WIN32
++# include <paths.h>
++#endif
++/* END PATCH for Guix */
++
+ /* locally defined functions */
+ static INT s_errno(void);
+ static iptr s_addr_in_heap(uptr x);
+@@ -746,6 +752,17 @@ static ptr s_process(char *s, IBOOL stderrp) {
+ 
+     INT tofds[2], fromfds[2], errfds[2];
+     struct sigaction act, oint_act;
++    /* BEGIN PATCH for Guix */
++#if defined(_PATH_BSHELL)
++    struct stat guix_stat_buf;
++    char *guix_sh =
++      (0 == stat(_PATH_BSHELL, &guix_stat_buf))
++      ? _PATH_BSHELL
++      : "/bin/sh";
++#else /* _PATH_BSHELL */
++    char *guix_sh = "/bin/sh";
++#endif
++    /* END PATCH for Guix */
+ 
+     if (pipe(tofds)) S_error("process","cannot open pipes");
+     if (pipe(fromfds)) {
+@@ -771,7 +788,9 @@ static ptr s_process(char *s, IBOOL stderrp) {
+         CLOSE(1); if (dup(fromfds[1]) != 1) _exit(1);
+         CLOSE(2); if (dup(stderrp ? errfds[1] : 1) != 2) _exit(1);
+         {INT i; for (i = 3; i < NOFILE; i++) (void)CLOSE(i);}
+-        execl("/bin/sh", "/bin/sh", "-c", s, NULL);
++        /* BEGIN PATCH for Guix */
++        execl(guix_sh, guix_sh, "-c", s, NULL);
++        /* END PATCH for Guix */
+         _exit(1) /* only if execl fails */;
+         /*NOTREACHED*/
+     } else {
+
+base-commit: 9df56e7b25bc523663eac3da24be33afc5f76c84
+-- 
+2.32.0
+
diff --git a/gnu/packages/patches/racket-chez-scheme-bin-sh.patch b/gnu/packages/patches/racket-chez-scheme-bin-sh.patch
new file mode 100644
index 0000000000..65cf2f99f3
--- /dev/null
+++ b/gnu/packages/patches/racket-chez-scheme-bin-sh.patch
@@ -0,0 +1,76 @@
+From e982b6687494bf071386c67be74e57a29cf4ce00 Mon Sep 17 00:00:00 2001
+From: Philip McGrath <philip@philipmcgrath.com>
+Date: Wed, 24 Aug 2022 19:55:14 -0400
+Subject: [PATCH] Chez Scheme: patch s_process for "/bin/sh" on Guix
+
+If:
+
+    1. The nonstandard but ubiquitous macro `_PATH_BSHELL` from
+       <paths.h> is defined; and
+
+    2. The path specified by `_PATH_BSHELL` exists;
+
+then `s_process` will call `execl` with the file specified by
+`_PATH_BSHELL` instead of "/bin/sh".
+
+Checking that the path specified by `_PATH_BSHELL` exists safeguards
+against obscure errors if attempting to use stand-alone executables
+built by the patched Racket in non-Guix envoronments.
+
+This patch does not change the behavior of `s_system`, which relies
+on `system` from the C library.
+---
+ racket/src/ChezScheme/c/prim5.c | 21 ++++++++++++++++++++-
+ 1 file changed, 20 insertions(+), 1 deletion(-)
+
+diff --git a/racket/src/ChezScheme/c/prim5.c b/racket/src/ChezScheme/c/prim5.c
+index f5e3e345be..922421ca75 100644
+--- a/racket/src/ChezScheme/c/prim5.c
++++ b/racket/src/ChezScheme/c/prim5.c
+@@ -22,6 +22,12 @@
+ #include <limits.h>
+ #include <ctype.h>
+ 
++/* BEGIN PATCH for Guix */
++#ifndef WIN32
++# include <paths.h>
++#endif
++/* END PATCH for Guix */
++
+ /* locally defined functions */
+ static INT s_errno PROTO((void));
+ static IBOOL s_addr_in_heap PROTO((uptr x));
+@@ -856,6 +862,17 @@ static ptr s_process(s, stderrp) char *s; IBOOL stderrp; {
+ 
+     INT tofds[2], fromfds[2], errfds[2];
+     struct sigaction act, oint_act;
++    /* BEGIN PATCH for Guix */
++#if defined(_PATH_BSHELL)
++    struct stat guix_stat_buf;
++    char *guix_sh =
++      (0 == stat(_PATH_BSHELL, &guix_stat_buf))
++      ? _PATH_BSHELL
++      : "/bin/sh";
++#else /* _PATH_BSHELL */
++    char *guix_sh = "/bin/sh";
++#endif
++    /* END PATCH for Guix */
+ 
+     if (pipe(tofds)) S_error("process","cannot open pipes");
+     if (pipe(fromfds)) {
+@@ -881,7 +898,9 @@ static ptr s_process(s, stderrp) char *s; IBOOL stderrp; {
+         CLOSE(1); if (dup(fromfds[1]) != 1) _exit(1);
+         CLOSE(2); if (dup(stderrp ? errfds[1] : 1) != 2) _exit(1);
+         {INT i; for (i = 3; i < NOFILE; i++) (void)CLOSE(i);}
+-        execl("/bin/sh", "/bin/sh", "-c", s, NULL);
++        /* BEGIN PATCH for Guix */
++        execl(guix_sh, guix_sh, "-c", s, NULL);
++        /* END PATCH for Guix */
+         _exit(1) /* only if execl fails */;
+         /*NOTREACHED*/
+     } else {
+
+base-commit: 9d228d16fb99c274c964e5bef93e97333888769f
+-- 
+2.32.0
+
diff --git a/gnu/packages/racket.scm b/gnu/packages/racket.scm
index 319f63f9d2..0f766e7850 100644
--- a/gnu/packages/racket.scm
+++ b/gnu/packages/racket.scm
@@ -211,7 +211,8 @@ (define %racket-origin
     (sha256
      (base32 "0f9zyhdvbh4xsndrqjzl85j5ziz0rmqi676g9s1lw3h3skq2636h"))
     (file-name (git-file-name "racket" %racket-version))
-    (patches (search-patches "racket-rktio-bin-sh.patch"))
+    (patches (search-patches "racket-chez-scheme-bin-sh.patch"
+                             "racket-rktio-bin-sh.patch"))
     (modules '((guix build utils)))
     (snippet
      #~(begin
-- 
2.32.0