[PATCH] compositor: Verify XDG_RUNTIME_DIR variable

[Martin Minarik]

Print an user friendly error mesage when
the variable is not a valid directory.
---
 src/compositor.c |   34 +++++++++++++++++++++++++++++-----
 1 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/src/compositor.c b/src/compositor.c
index d40a878..f5940aa 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -39,6 +39,7 @@
 #include <sys/wait.h>
 #include <sys/socket.h>
 #include <sys/utsname.h>
+#include <sys/stat.h>
 #include <unistd.h>
 #include <math.h>
 #include <linux/input.h>
@@ -3145,11 +3146,37 @@ load_module(const char *name, const char *entrypoint, void **handle)
 }
 
 static const char xdg_error_message[] =
-	"fatal: environment variable XDG_RUNTIME_DIR is not set.\n"
+	"fatal: environment variable XDG_RUNTIME_DIR is not set.\n";
+
+static const char xdg_wrong_message[] =
+	"fatal: environment variable XDG_RUNTIME_DIR\n"
+	"is set to \"%s\". This is not a correct directory.\n";
+
+static const char xdg_detail_message[] =
 	"Refer to your distribution on how to get it, or\n"
 	"http://www.freedesktop.org/wiki/Specifications/basedir-spec\n"
 	"on how to implement it.\n";
 
+static void
+verify_xdg_runtime_dir()
+{
+	char * dir = getenv("XDG_RUNTIME_DIR");
+	struct stat s;
+
+	if (!dir) {
+		weston_log(xdg_error_message);
+		weston_log_continue(xdg_detail_message);
+		exit(EXIT_FAILURE);
+	} else {
+		stat(dir, &s);
+		if (!S_ISDIR(s.st_mode)) {
+			weston_log(xdg_wrong_message, dir);
+			weston_log_continue(xdg_detail_message);
+			exit(EXIT_FAILURE);
+		}
+	}
+}
+
 int main(int argc, char *argv[])
 {
 	int ret = EXIT_SUCCESS;
@@ -3196,10 +3223,7 @@ int main(int argc, char *argv[])
 
 	weston_log_file_open(log);
 	
-	if (!getenv("XDG_RUNTIME_DIR")) {
-		weston_log(xdg_error_message);
-		exit(EXIT_FAILURE);
-	}
+	verify_xdg_runtime_dir();
 
 	weston_log("%s\n"
 		   STAMP_SPACE "%s\n"
-- 
1.7.5.4