Bug 1336048 - Add display detection to dom/ipc/ContentChild.cpp, r=glandium

MozReview-Commit-ID: CwcGXFiIl4e

--HG--
extra : rebase_source : 04a6b70562cf292f2d5ba45b8e72788684f3baa8

dom/ipc/ContentChild.cpp

@@ -201,6 +201,11 @@
 #include "nscore.h" // for NS_FREE_PERMANENT_DATA
 #include "VRManagerChild.h"
 
+#ifdef MOZ_WIDGET_GTK
+#include "nsAppRunner.h"
+#endif
+
+
 using namespace mozilla;
 using namespace mozilla::docshell;
 using namespace mozilla::dom::devicestorage;
@@ -527,7 +532,7 @@ ContentChild::Init(MessageLoop* aIOLoop,
   // to use, and when starting under XWayland, it may choose to start with
   // the wayland backend instead of the x11 backend.
   // The DISPLAY environment variable is normally set by the parent process.
-  char* display_name = PR_GetEnv("DISPLAY");
+  const char* display_name = DetectDisplay();
   if (display_name) {
     int argc = 3;
     char option_name[] = "--display";
@@ -536,7 +541,7 @@ ContentChild::Init(MessageLoop* aIOLoop,
       // XRE_InitChildProcess().
       nullptr,
       option_name,
-      display_name,
+      const_cast<char*>(display_name),
       nullptr
     };
     char** argvp = argv;

toolkit/xre/nsAppRunner.cpp

@@ -2892,7 +2892,7 @@ static void MOZ_gdk_display_close(GdkDisplay *display)
 #endif
 }
 
-static const char* detectDisplay(void)
+const char* DetectDisplay(void)
 {
   bool tryX11 = false;
   bool tryWayland = false;
@@ -3750,7 +3750,7 @@ XREMain::XRE_mainStartup(bool* aExitFlag)
   if (display_name) {
     saveDisplayArg = true;
   } else {
-    display_name = detectDisplay();
+    display_name = DetectDisplay();
     if (!display_name) {
       return 1;
     }

toolkit/xre/nsAppRunner.h

@@ -133,4 +133,8 @@ void SetupErrorHandling(const char* progname);
  */
 uint32_t MultiprocessBlockPolicy();
 
+#ifdef MOZ_WIDGET_GTK
+const char* DetectDisplay();
+#endif
+
 #endif // nsAppRunner_h__