gnu: chez-scheme: Fix use of "/bin/sh".

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.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 76 insertions, 0 deletions

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
+