PlzNavigate: preserve SourceLocation when navigating

third_party/WebKit/Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 5790 matching lines @@
             BLINK_FROM_HERE,
             crossThreadBind(&runAddConsoleMessageTask, consoleMessage->source(),
                             consoleMessage->level(), consoleMessage->message(),
                             wrapCrossThreadPersistent(this)));
     return;
   }
 
   if (!m_frame)
     return;
 
+  // PlzNavigate: when trying to commit a navigation, the SourceLocation
+  // information for how the request was triggered has been stored in the
+  // provisional DocumentLoader. Use it instead.
+  DocumentLoader* provisionalLoader =
+      m_frame->loader().provisionalDocumentLoader();

[Nate Chapin, 2017/03/01 23:22:19]

This seems wrong. Anything going through a Document should be associated with
the committed DocumentLoader, not the provisional DocumentLoader. What depends
on this?

[clamy, 2017/03/02 13:34:32]

I thought the message I whose SourceLocation I needed to change went through
this function, but actually it goes directly through the FrameConsole. Removed
that part.

+  if (provisionalLoader) {
+    std::unique_ptr<SourceLocation> sourceLocation =
+        provisionalLoader->copySourceLocation();
+    if (sourceLocation) {
+      consoleMessage = ConsoleMessage::create(
+          consoleMessage->source(), consoleMessage->level(),
+          consoleMessage->message(), std::move(sourceLocation));
+    }
+  }
+
   if (consoleMessage->location()->isUnknown()) {
     // TODO(dgozman): capture correct location at call places instead.
     unsigned lineNumber = 0;
     if (!isInDocumentWrite() && scriptableDocumentParser()) {
       ScriptableDocumentParser* parser = scriptableDocumentParser();
       if (parser->isParsingAtLineNumber())
         lineNumber = parser->lineNumber().oneBasedInt();
     }
     consoleMessage = ConsoleMessage::create(
         consoleMessage->source(), consoleMessage->level(),
@@ skipping 840 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (blink::Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->url().getString().utf8().data());
 }
 #endif