From eb7c78631445f35737d059bea23174d972cf7ca3 Mon Sep 17 00:00:00 2001
From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Tue, 16 Jul 2019 07:03:12 -0700
Subject: mingw: support spawning programs containing spaces in their names

On some older Windows versions (e.g. Windows 7), the CreateProcessW()
function does not really support spaces in its first argument,
lpApplicationName. But it supports passing NULL as lpApplicationName,
which makes it figure out the application from the (possibly quoted)
first argument of lpCommandLine.

Let's use that trick (if we are certain that the first argument matches
the executable's path) to support launching programs whose path contains
spaces.

We will abuse the test-fake-ssh.exe helper to verify that this works and
does not regress.

This fixes https://github.com/git-for-windows/git/issues/692

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/compat/mingw.c b/compat/mingw.c
index 9b6d240..6d7fc07 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -1437,7 +1437,9 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 	si.hStdOutput = winansi_get_osfhandle(fhout);
 	si.hStdError = winansi_get_osfhandle(fherr);
 
-	if (xutftowcs_path(wcmd, cmd) < 0)
+	if (*argv && !strcmp(cmd, *argv))
+		wcmd[0] = L'\0';
+	else if (xutftowcs_path(wcmd, cmd) < 0)
 		return -1;
 	if (dir && xutftowcs_path(wdir, dir) < 0)
 		return -1;
@@ -1466,8 +1468,8 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 	wenvblk = make_environment_block(deltaenv);
 
 	memset(&pi, 0, sizeof(pi));
-	ret = CreateProcessW(wcmd, wargs, NULL, NULL, TRUE, flags,
-		wenvblk, dir ? wdir : NULL, &si, &pi);
+	ret = CreateProcessW(*wcmd ? wcmd : NULL, wargs, NULL, NULL, TRUE,
+		flags, wenvblk, dir ? wdir : NULL, &si, &pi);
 
 	free(wenvblk);
 	free(wargs);
diff --git a/t/t0061-run-command.sh b/t/t0061-run-command.sh
index ebc4956..015fac8 100755
--- a/t/t0061-run-command.sh
+++ b/t/t0061-run-command.sh
@@ -210,4 +210,10 @@ test_expect_success MINGW 'verify curlies are quoted properly' '
 	test_cmp expect actual
 '
 
+test_expect_success MINGW 'can spawn with argv[0] containing spaces' '
+	cp "$GIT_BUILD_DIR/t/helper/test-fake-ssh$X" ./ &&
+	test_must_fail "$PWD/test-fake-ssh$X" 2>err &&
+	grep TRASH_DIRECTORY err
+'
+
 test_done
-- 
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