Issue #1757 - Reinstate "dom.details_element.enabled" preference

The removal of this preference was botched, all other surrounding plumbing changes appear to be working okay. The ability to use prefs to control this stylesheet might be useful in the future, so perhaps this is one of those "if it ain't broke, don't fix it" bugs where leaving well enough alone in the first place would have been the best choice.

1 files changed, 8 insertions, 2 deletions

diff --git a/layout/style/nsLayoutStylesheetCache.cpp b/layout/style/nsLayoutStylesheetCache.cpp
index bf87b006ca..1905d8c5cd 100644
--- a/layout/style/nsLayoutStylesheetCache.cpp
+++ b/layout/style/nsLayoutStylesheetCache.cpp
@@ -121,6 +121,11 @@ nsLayoutStylesheetCache::UASheet()
 StyleSheet*
 nsLayoutStylesheetCache::HTMLSheet()
 {
+  if (!mHTMLSheet) {
+    LoadSheetURL("resource://gre-resources/html.css",
+                 &mHTMLSheet, eAgentSheetFeatures, eCrash);
+  }
+
   return mHTMLSheet;
 }
 
@@ -316,8 +321,6 @@ nsLayoutStylesheetCache::nsLayoutStylesheetCache(StyleBackendType aType)
   // per-profile, since they're profile-invariant.
   LoadSheetURL("resource://gre-resources/counterstyles.css",
                &mCounterStylesSheet, eAgentSheetFeatures, eCrash);
-  LoadSheetURL("resource://gre-resources/html.css",
-               &mHTMLSheet, eAgentSheetFeatures, eCrash);
   LoadSheetURL("chrome://global/content/minimal-xul.css",
                &mMinimalXULSheet, eAgentSheetFeatures, eCrash);
   LoadSheetURL("resource://gre-resources/quirk.css",
@@ -378,6 +381,8 @@ nsLayoutStylesheetCache::For(StyleBackendType aType)
     //                               "layout.css.example-pref.enabled");
     Preferences::RegisterCallback(&DependentPrefChanged,
                                   "layout.css.grid.enabled");
+    Preferences::RegisterCallback(&DependentPrefChanged,
+                                  "dom.details_element.enabled");
   }
 
   return cache;
@@ -549,6 +554,7 @@ nsLayoutStylesheetCache::DependentPrefChanged(const char* aPref, void* aData)
                   gStyleCache_Servo ? &gStyleCache_Servo->sheet_ : nullptr);
 
   INVALIDATE(mUASheet);  // for layout.css.grid.enabled
+  INVALIDATE(mHTMLSheet); // for dom.details_element.enabled
 
 #undef INVALIDATE
 }