Bug 167577

Thread 1 (Thread 0x7ff3e7c27940 (LWP 19299)): #0 0x00007ff3f7776b11 in WebCore::insertPerformanceEntry(WTF::HashMap<WTF::String, WTF::Vector<WTF::RefPtr<WebCore::PerformanceEntry>, 0ul, WTF::CrashOnOverflow, 16ul>, WTF::StringHash, WTF::HashTraits<WTF::String>, WTF::HashTraits<WTF::Vector<WTF::RefPtr<WebCore::PerformanceEntry>, 0ul, WTF::CrashOnOverflow, 16ul> > >&, WTF::Ref<WebCore::PerformanceEntry>&&) () from /home/slave/webkitgtk/gtk-linux-64-release/build/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #1 0x00007ff3f7776dec in WebCore::UserTiming::mark(WTF::String const&) () from /home/slave/webkitgtk/gtk-linux-64-release/build/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #2 0x00007ff3f7771634 in WebCore::Performance::mark(WTF::String const&) () from /home/slave/webkitgtk/gtk-linux-64-release/build/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #3 0x00007ff3f815c2fb in WebCore::jsPerformancePrototypeFunctionMark(JSC::ExecState*) () from /home/slave/webkitgtk/gtk-linux-64-release/build/WebKitBuild/Release/lib/libwebkit2gtk-4.0.so.37 #4 0x00007ff3a6ffe028 in ?? () #5 0x00007fffc0588b80 in ?? () #6 0x00007ff3f47345e0 in llint_entry () from /home/slave/webkitgtk/gtk-linux-64-release/build/WebKitBuild/Release/lib/libjavascriptcoregtk-4.0.so.18 Backtrace stopped: frame did not save the PC I think this doesn't happen in other bots because of the compiler version. The problem is that entry is used in both the key, to get name, and in the value with WTFMove. So, the name is invalidated by the move. It could be fixed by simply copying the name, instead of using entry->name, but I think that code could be simplified using HashMap::ensure and then we don't need any string copy, nor even the static insertPerformanceEntry().