Bug 1895092 - Ensure linux gtk theme is "Adwaita" for reftests. r=dholbert, a=dmeehan

Differential Revision: https://phabricator.services.mozilla.com/D209618

layout/tools/reftest/runreftest.py

@@ -303,6 +303,7 @@ class RefTest(object):
         self.outputHandler = None
         self.testDumpFile = os.path.join(tempfile.gettempdir(), "reftests.json")
         self.currentManifest = "No test started"
+        self.gtkTheme = self.getGtkTheme()
 
         self.run_by_manifest = True
         if suite in ("crashtest", "jstestbrowser"):
@@ -329,6 +330,17 @@ class RefTest(object):
             "reftest harness", options, {"tbpl": sys.stdout}, fmt_options
         )
 
+    def getGtkTheme(self):
+        if not platform.system() == "Linux":
+            return ""
+
+        theme_cmd = "gsettings get org.gnome.desktop.interface gtk-theme"
+        theme = subprocess.check_output(theme_cmd, shell=True, universal_newlines=True)
+        if theme:
+            theme = theme.strip("\n")
+            theme = theme.strip("'")
+        return theme.strip()
+
     def getFullPath(self, path):
         "Get an absolute path relative to self.oldcwd."
         return os.path.normpath(os.path.join(self.oldcwd, os.path.expanduser(path)))
@@ -564,6 +576,9 @@ class RefTest(object):
             browserEnv["TZ"] = "PST8PDT"
             browserEnv["LC_ALL"] = "en_US.UTF-8"
 
+        # This should help with consistency
+        browserEnv["GTK_THEME"] = "Adwaita"
+
         for v in options.environment:
             ix = v.find("=")
             if ix <= 0:
@@ -1127,6 +1142,13 @@ class RefTest(object):
         overall = 0
         status = -1
         for manifest, tests in tests_by_manifest.items():
+            if self.getGtkTheme() != self.gtkTheme:
+                self.log.error(
+                    "Theme (%s) has changed to (%s), terminating job as this is unstable"
+                    % (self.gtkTheme, self.getGtkTheme())
+                )
+                return 1
+
             self.log.info("Running tests in {}".format(manifest))
             self.currentManifest = manifest
             status = run(tests=tests)