run-command: refine Git LFS check on Windows 7

In commit git-for-windows/git@46d14a6 of
PR git-for-windows#5042 the wait_or_whine() function in run-command.c
was revised to call a new function in the case where an executable fails
to run, to check whether this was caused by a Git LFS binary compiled
with a version of the Go language that no longer supports Windows 7.
This change was made to address the issue reported in
git-for-windows#4996.

The new function, win32_warn_about_git_lfs_on_windows7(), performs
several initial checks to test whether the failed executable returned
the exit code 0x0b00 and is named "git-lfs", and whether we are
running Windows 7 or not.  Only if all these conditions are met does
it then proceed to try to extract the Go language version from the
binary file and check whether it is 1.21.0 or higher.

However, these initial checks may not cover all possible use and
failure cases.

First, when running in Git Bash, the exit code seen from a recent
Git LFS executable was 0x02, so we also want to check for that value
as well as 0x0b00.

Second, the name of the executable may not always be entirely lowercase,
since it is possible to invoke Git LFS through Git by running, for
example, "git LFS ls-files" (at least, on Windows, and with a
case-insensitive filesystem).  We therefore need to ignore case when
checking the executable's name.

And third, the name of the executable may not have a trailing space
character, so we also need to check for the case where the name in
argv0 is simply "git-lfs".

With these changes, we can more reliably detect a failure of the Git LFS
executable in a wider range of circumstances.

Signed-off-by: Chris Darroch <[email protected]>

compat/win32/path-utils.c

@@ -222,13 +222,17 @@ void win32_warn_about_git_lfs_on_windows7(int exit_code, const char *argv0)
 	 * would usually show up as an exit code 0xc0000005. For some reason
 	 * (probably because at this point, we no longer have the _original_
 	 * HANDLE that was returned by `CreateProcess()`) we get 0xb00 instead.
+	 * When running in Git Bash we get exit code 2, so we check for that
+	 * as well.
 	 */
-	if (exit_code != 0x0b00)
+	if (exit_code != 0x0002 && exit_code != 0x0b00)
 		return;
 	if (GetVersion() >> 16 > 7601)
 		return; /* Warn only on Windows 7 or older */
-	if (!starts_with(argv0, "git-lfs ") ||
-	    !(git_lfs = locate_in_PATH("git-lfs")))
+	if (!istarts_with(argv0, "git-lfs ") &&
+	    strcasecmp(argv0, "git-lfs"))
+		return;
+	if (!(git_lfs = locate_in_PATH("git-lfs")))
 		return;
 	if (get_go_version(git_lfs, buffer, sizeof(buffer)) > 0 &&
 	    skip_prefix(buffer, "go", &p) &&