Fix gpu line dashing when line is zero length but has cap

Bug: skia:7387
Change-Id: I49a023f395ab1539c80881f95242a4bdad6e70b3
Reviewed-on: https://skia-review.googlesource.com/79722
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/gm/dashing.cpp b/gm/dashing.cpp
index a46d31f471..277769198a 100644
--- a/gm/dashing.cpp
+++ b/gm/dashing.cpp
@@ -332,7 +332,7 @@ protected:
         return SkString("dashing4");
     }
 
-    SkISize onISize() { return SkISize::Make(640, 1050); }
+    SkISize onISize() { return SkISize::Make(640, 1100); }
 
     virtual void onDraw(SkCanvas* canvas) {
         constexpr struct {
@@ -409,6 +409,16 @@ protected:
         canvas->translate(0, SkIntToScalar(50));
         paint.setStrokeCap(SkPaint::kSquare_Cap);
         drawline(canvas, 0, 30, paint);
+
+        // Test we draw the cap when the line length is zero.
+        canvas->translate(0, SkIntToScalar(50));
+        paint.setStrokeCap(SkPaint::kRound_Cap);
+        paint.setColor(0xFF000000);
+        paint.setStrokeWidth(11);
+        drawline(canvas, 0, 30, paint, 0);
+
+        canvas->translate(SkIntToScalar(100), 0);
+        drawline(canvas, 1, 30, paint, 0);
     }
 };