Reset GL glyph cache when texture limit is reached

This is a port of 72f161739b270b01807f97cd853030440f0fd430 which was
reverted in integration to master, since it was incompatible with
the refactored glyph cache.

When the GL glyph cache reached its texture limit, we have to reset it
and start over. Added a new cleanup() function in
QGLContextGroupResourceBase which deletes the resource for a given
context and removes itself from that context group.

Task-number: QTBUG-13784
Reviewed-by: Samuel

1 files changed, 5 insertions, 0 deletions

diff --git a/src/gui/painting/qtextureglyphcache.cpp b/src/gui/painting/qtextureglyphcache.cpp
index b83dbc057f..eab02e1d25 100644
--- a/src/gui/painting/qtextureglyphcache.cpp
+++ b/src/gui/painting/qtextureglyphcache.cpp
@@ -238,6 +238,11 @@ bool QTextureGlyphCache::populate(QFontEngine *fontEngine, int numGlyphs, const
             }
         }
 
+        if (maxTextureHeight() > 0 && m_cy + c.h > maxTextureHeight()) {
+            // We can't make a cache of the required size, so we bail out
+            return false;
+        }
+
         c.x = m_cx;
         c.y = m_cy;