var(win32): do report the GIT_SHELL_PATH that is actually used

On Windows, Unix-like paths like `/bin/sh` make very little sense. In
the best case, they simply don't work, in the worst case they are
misinterpreted as absolute paths that are relative to the drive
associated with the current directory.

To that end, Git does not actually use the path `/bin/sh` that is
recorded e.g. when `run_command()` is called with a Unix shell
command-line. Instead, as of 776297548e (Do not use SHELL_PATH from
build system in prepare_shell_cmd on Windows, 2012-04-17), it
re-interprets `/bin/sh` as "look up `sh` on the `PATH` and use the
result instead".

This is the logic users expect to be followed when running `git var
GIT_SHELL_PATH`.

However, when 1e65721227 (var: add support for listing the shell,
2023-06-27) introduced support for `git var GIT_SHELL_PATH`, Windows was
not special-cased as above, which is why it outputs `/bin/sh` even
though that disagrees with what Git actually uses.

Let's fix this by using the exact same logic as `prepare_shell_cmd()`,
adjusting the Windows-specific `git var GIT_SHELL_PATH` test case to
verify that it actually finds a working executable.

Reported-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/var.c b/builtin/var.c
index 5dc384810c0969eb267707f675320e15e02a99b1..e30ff45be1ce730633d84cfc9c5caf0dab187dd1 100644 (file)
--- a/builtin/var.c
+++ b/builtin/var.c
@@ -12,6 +12,7 @@
 #include "refs.h"
 #include "path.h"
 #include "strbuf.h"
+#include "run-command.h"
 
 static const char var_usage[] = "git var (-l | <variable>)";
 
@@ -51,7 +52,7 @@ static char *default_branch(int ident_flag UNUSED)
 
 static char *shell_path(int ident_flag UNUSED)
 {
-       return xstrdup(SHELL_PATH);
+       return git_shell_path();
 }
 
 static char *git_attr_val_system(int ident_flag UNUSED)

diff --git a/t/t0007-git-var.sh b/t/t0007-git-var.sh
index ff4fd9348cca6470f4dbacbc4c9a3d775f15c06d..9fc5882387390aa8b30477c2037d28cefeea64fc 100755 (executable)
--- a/t/t0007-git-var.sh
+++ b/t/t0007-git-var.sh
@@ -157,7 +157,7 @@ test_expect_success POSIXPERM 'GIT_SHELL_PATH points to a valid executable' '
 test_expect_success MINGW 'GIT_SHELL_PATH points to a suitable shell' '
        shellpath=$(git var GIT_SHELL_PATH) &&
        case "$shellpath" in
-       *sh) ;;
+       [A-Z]:/*/sh.exe) test -f "$shellpath";;
        *) return 1;;
        esac
 '