http-backend: add GIT_PROJECT_ROOT environment var

Add a new environment variable, GIT_PROJECT_ROOT, to override the
method of using PATH_TRANSLATED to find the git repository on disk.
This makes it much easier to configure the web server, especially when
the web server's DocumentRoot does not contain the git repositories,
which is the usual case.

Signed-off-by: Mark Lodato <lodatom@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 22 insertions, 3 deletions

diff --git a/http-backend.c b/http-backend.c
index bfce52063f..7900cda69a 100644
--- a/http-backend.c
+++ b/http-backend.c
@@ -528,6 +528,26 @@ static NORETURN void die_webcgi(const char *err, va_list params)
 	exit(0);
 }
 
+static char* getdir(void)
+{
+	struct strbuf buf = STRBUF_INIT;
+	char *pathinfo = getenv("PATH_INFO");
+	char *root = getenv("GIT_PROJECT_ROOT");
+	char *path = getenv("PATH_TRANSLATED");
+
+	if (root && *root) {
+		if (!pathinfo || !*pathinfo)
+			die("GIT_PROJECT_ROOT is set but PATH_INFO is not");
+		strbuf_addstr(&buf, root);
+		strbuf_addstr(&buf, pathinfo);
+		return strbuf_detach(&buf, NULL);
+	} else if (path && *path) {
+		return xstrdup(path);
+	} else
+		die("No GIT_PROJECT_ROOT or PATH_TRANSLATED from server");
+	return NULL;
+}
+
 static struct service_cmd {
 	const char *method;
 	const char *pattern;
@@ -549,7 +569,7 @@ static struct service_cmd {
 int main(int argc, char **argv)
 {
 	char *method = getenv("REQUEST_METHOD");
-	char *dir = getenv("PATH_TRANSLATED");
+	char *dir;
 	struct service_cmd *cmd = NULL;
 	char *cmd_arg = NULL;
 	int i;
@@ -561,8 +581,7 @@ int main(int argc, char **argv)
 		die("No REQUEST_METHOD from server");
 	if (!strcmp(method, "HEAD"))
 		method = "GET";
-	if (!dir)
-		die("No PATH_TRANSLATED from server");
+	dir = getdir();
 
 	for (i = 0; i < ARRAY_SIZE(services); i++) {
 		struct service_cmd *c = &services[i];