Index: src/app/qgslabeldialog.cpp
===================================================================
--- src/app/qgslabeldialog.cpp	(revision 13746)
+++ src/app/qgslabeldialog.cpp	(working copy)
@@ -294,33 +294,40 @@
       // font is set to the font the user selected
       spinFontSize->setValue( mFont.pointSizeF() );
     }
+    lblSample->setFont( mFont );
   }
   else
   {
-    // the user cancelled the dialog; font is set to the initial
-    // value, in this case Helvetica [Cronyx], 10
+    // the user cancelled the dialog; so don't change anything
   }
-  lblSample->setFont( mFont );
 }
 
 void QgsLabelDialog::changeFontColor( void )
 {
   QgsDebugMsg( "entering." );
 
-  mFontColor = QColorDialog::getColor( mFontColor );
-  QPalette palette = lblSample->palette();
-  palette.setColor( lblSample->foregroundRole(), mFontColor );
-  lblSample->setPalette( palette );
+  QColor color = QColorDialog::getColor( mFontColor );
+  if ( color.isValid() ) 
+  {
+    mFontColor = color;
+    QPalette palette = lblSample->palette();
+    palette.setColor( lblSample->foregroundRole(), mFontColor );
+    lblSample->setPalette( palette );
+  }
 }
 
 void QgsLabelDialog::changeBufferColor( void )
 {
   QgsDebugMsg( "entering." );
 
-  mBufferColor = QColorDialog::getColor( mBufferColor );
-  QPalette palette = lblSample->palette();
-  palette.setColor( lblSample->backgroundRole(), mBufferColor );
-  lblSample->setPalette( palette );
+  QColor color = QColorDialog::getColor( mBufferColor );
+  if ( color.isValid() ) 
+  {
+    mBufferColor = color;
+    QPalette palette = lblSample->palette();
+    palette.setColor( lblSample->backgroundRole(), mBufferColor );
+    lblSample->setPalette( palette );
+  }
 }