Assertion failure when adding duplicate "spawnflags" key and trying to edit spawnflags.

[ericwa]

Tested on fc9908f / OS X.
Steps to reproduce:

1. Create a New map, choose quake

2. Copy and paste at original position:

   {
   "spawnflags" "0"
   "classname" "misc_model"
   "origin" "-16 -864 32"
   "angle" "-0"
   "_shadow" "1"
   }
   

3. select the entities tab. Click + to add a new key and type "spawnflags" + enter. The new key is merged with the existing "spawnflags" key.

4. Double-click on the value box for "spawnflags". An assertion fails:

Assertion failed: (matches.size() == 1), function findAttribute, file /Users/ericwa/dev/TrenchBroom/common/src/Model/EntityAttributes.cpp, line 280.

(lldb) bt
* thread #1: tid = 0x16748, 0x00007fff919f6002 libsystem_kernel.dylib`__pthread_kill + 10, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
    frame #0: 0x00007fff919f6002 libsystem_kernel.dylib`__pthread_kill + 10
    frame #1: 0x000000010331244e libsystem_pthread.dylib`pthread_kill + 90
    frame #2: 0x00007fff838c36e7 libsystem_c.dylib`abort + 129
    frame #3: 0x00007fff8388adf8 libsystem_c.dylib`__assert_rtn + 321
  * frame #4: 0x0000000100170e3a TrenchBroom`TrenchBroom::Model::EntityAttributes::findAttribute(this=0x00006130003beb88, name="spawnflags") const + 234 at EntityAttributes.cpp:280
    frame #5: 0x0000000100170d1f TrenchBroom`TrenchBroom::Model::EntityAttributes::hasAttribute(this=0x00006130003beb88, name="spawnflags") const + 47 at EntityAttributes.cpp:206
    frame #6: 0x000000010011888f TrenchBroom`TrenchBroom::Model::AttributableNode::hasAttribute(this=0x00006130003beb00, name="spawnflags") const + 47 at AttributableNode.cpp:127
    frame #7: 0x00000001005282d7 TrenchBroom`TrenchBroom::View::SmartSpawnflagsEditor::getFlagValue(this=0x000060f000099790, attributable=0x00006130003beb00) const + 55 at SmartSpawnflagsEditor.cpp:190
    frame #8: 0x00000001005281ae TrenchBroom`TrenchBroom::View::SmartSpawnflagsEditor::getFlagValues(this=0x000060f000099790, attributables=size=1, setFlags=0x00007fff5fbfe5c0, mixedFlags=0x00007fff5fbfe5bc) const + 126 at SmartSpawnflagsEditor.cpp:182
    frame #9: 0x0000000100527cd2 TrenchBroom`TrenchBroom::View::SmartSpawnflagsEditor::doUpdateVisual(this=0x000060f000099790, attributables=size=1) + 210 at SmartSpawnflagsEditor.cpp:132
    frame #10: 0x0000000100515682 TrenchBroom`TrenchBroom::View::SmartAttributeEditor::updateVisual(this=0x000060f000099790, attributables=size=1) + 50 at SmartAttributeEditor.cpp:86
    frame #11: 0x0000000100515646 TrenchBroom`TrenchBroom::View::SmartAttributeEditor::update(this=0x000060f000099790, attributables=size=1) + 70 at SmartAttributeEditor.cpp:48
    frame #12: 0x000000010051841d TrenchBroom`TrenchBroom::View::SmartAttributeEditorManager::updateEditor(this=0x0000618000057880) + 189 at SmartAttributeEditorManager.cpp:136
    frame #13: 0x0000000100518132 TrenchBroom`TrenchBroom::View::SmartAttributeEditorManager::switchEditor(this=0x0000618000057880, name="spawnflags", attributables=size=1) + 130 at SmartAttributeEditorManager.cpp:54
    frame #14: 0x00000001003ac8a7 TrenchBroom`TrenchBroom::View::EntityAttributeEditor::OnEntityAttributeSelected(this=0x0000618000058c80, command=0x00007fff5fbfe918) + 215 at EntityAttributeEditor.cpp:48
    frame #15: 0x0000000100914fc9 TrenchBroom`wxEvtHandler::SearchDynamicEventTable(wxEvent&) + 185
    frame #16: 0x0000000100914d3b TrenchBroom`wxEvtHandler::ProcessEventLocally(wxEvent&) + 59
    frame #17: 0x0000000100914c4b TrenchBroom`wxEvtHandler::ProcessEvent(wxEvent&) + 187
    frame #18: 0x00000001003af530 TrenchBroom`TrenchBroom::View::EntityAttributeGrid::fireSelectionEvent(this=0x0000618000058480, row=0, col=1) + 288 at EntityAttributeGrid.cpp:98
    frame #19: 0x00000001003af405 TrenchBroom`TrenchBroom::View::EntityAttributeGrid::OnAttributeGridSelectCell(this=0x0000618000058480, event=0x00007fff5fbfeb10) + 101 at EntityAttributeGrid.cpp:60
....

The assertion fails because matches.size() is actually 2.

[kduske]

Fixed in adf2f66.