[gnome-shell/gnome-3-28] extensionSystem: Unload stylesheet if extension is not loaded

[Marco Trevisan <marcotrevi src gnome org>]

commit e027af9548282cc07a3428d9fc9fa763730adf46
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Fri Aug 3 15:52:19 2018 +0000

    extensionSystem: Unload stylesheet if extension is not loaded
    
    We should not keep any reference to an extension custom stylesheet in case we
    got an error while enabling that
    
    
    (cherry picked from commit 3aea290adcbf7d12e6d8ec8230afbd8c3cb74606)

 js/ui/extensionSystem.js | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/js/ui/extensionSystem.js b/js/ui/extensionSystem.js
index 3f23d273e..6611b5a63 100644
--- a/js/ui/extensionSystem.js
+++ b/js/ui/extensionSystem.js
@@ -136,6 +136,10 @@ function enableExtension(uuid) {
         _signals.emit('extension-state-changed', extension);
         return;
     } catch(e) {
+        if (extension.stylesheet) {
+            theme.unload_stylesheet(extension.stylesheet);
+            delete extension.stylesheet;
+        }
         logExtensionError(uuid, e);
         return;
     }