setup_work_tree: adjust relative $GIT_WORK_TREE after moving cwd

When setup_work_tree() is called, it moves cwd to $GIT_WORK_TREE and
makes internal copy of $GIT_WORK_TREE absolute. The environt variable,
if set by user, remains unchanged. If the variable is relative, it is
no longer correct because its base dir has changed.

Instead of making $GIT_WORK_TREE absolute too, we just say "." and let
subsequent git processes handle it.

Reported-by: Michel Briand <michelbriand@free.fr>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/test-subprocess.c b/test-subprocess.c
new file mode 100644
index 000000000..667d3e507
--- /dev/null
+++ b/test-subprocess.c
@@ -0,0 +1,21 @@
+#include "cache.h"
+#include "run-command.h"
+
+int main(int argc, char **argv)
+{
+	const char *prefix;
+	struct child_process cp;
+	int nogit = 0;
+
+	prefix = setup_git_directory_gently(&nogit);
+	if (nogit)
+		die("No git repo found");
+	if (!strcmp(argv[1], "--setup-work-tree")) {
+		setup_work_tree();
+		argv++;
+	}
+	memset(&cp, 0, sizeof(cp));
+	cp.git_cmd = 1;
+	cp.argv = (const char **)argv+1;
+	return run_command(&cp);
+}