Bug 1074475 - Fix a bug in GetStrokeDashData. r=longsonr

content/svg/content/src/SVGContentUtils.cpp

@@ -122,10 +122,21 @@ GetStrokeDashData(SVGContentUtils::AutoStrokeOptions* aStrokeOptions,
     }
   }
 
-  // Now that aStrokeOptions.mDashPattern is fully initialized we can safely
-  // set mDashLength:
+  // Now that aStrokeOptions.mDashPattern is fully initialized (we didn't
+  // return early above) we can safely set mDashLength:
   aStrokeOptions->mDashLength = dashArrayLength;
 
+  if ((dashArrayLength % 2) == 1) {
+    // If we have a dash pattern with an odd number of lengths the pattern
+    // repeats a second time, per the SVG spec., and as implemented by Moz2D.
+    // When deciding whether to return eNoStroke or eContinuousStroke below we
+    // need to take into account that in the repeat pattern the dashes become
+    // gaps, and the gaps become dashes.
+    Float origTotalLengthOfDashes = totalLengthOfDashes;
+    totalLengthOfDashes += totalLengthOfGaps;
+    totalLengthOfGaps += origTotalLengthOfDashes;
+  }
+
   if (totalLengthOfDashes <= 0 || totalLengthOfGaps <= 0) {
     if (totalLengthOfGaps > 0 && totalLengthOfDashes <= 0) {
       return eNoStroke;