[LyX/master] fix Symbols dialog box grid size in case of broken QFontMetrics::maxWidth()

[Stephan Witt]

commit 358e9ab31b489e9b98ebe278a900845ebb1c5329
Author: Stephan Witt <sw...@lyx.org>
Date:   Sat Jan 4 20:14:06 2014 +0100

    fix Symbols dialog box grid size in case of broken QFontMetrics::maxWidth()

diff --git a/src/frontends/qt4/GuiSymbols.cpp b/src/frontends/qt4/GuiSymbols.cpp
index 874f275..743cab7 100644
--- a/src/frontends/qt4/GuiSymbols.cpp
+++ b/src/frontends/qt4/GuiSymbols.cpp
@@ -277,12 +277,16 @@ GuiSymbols::GuiSymbols(GuiView & lv)
 
        symbolsLW->setViewMode(QListView::IconMode);
        // increase the display size of the symbols a bit
-       QFont font= symbolsLW->font();
-       int size = font.pointSize() + 3;
+       QFont font = symbolsLW->font();
+       const int size = font.pointSize() + 3;
        font.setPointSize(size);
        symbolsLW->setFont(font);
        QFontMetrics fm(font);
-       symbolsLW->setGridSize(QSize(fm.maxWidth() + 2, fm.height() + 2));
+       const int cellHeight = fm.height() + 2;
+       // FIXME: using at least cellHeight because of
+       // QFontMetrics::maxWidth() is returning 0 with Qt/Cocoa on Mac OS
+       const int cellWidth = max(cellHeight, fm.maxWidth() + 2);
+       symbolsLW->setGridSize(QSize(cellWidth, cellHeight));
        symbolsLW->setModel(model_);
 }