Avoid drawing NVPR DIF text when text size is 0

Avoid drawing text when using NVPR and device independent fonts.
The drawing calculations cause division by zero and produce NaNs
to transforms (due to fTextInverseRatio).

Reproed by top25desk_twitter.skp as well as the added testcase.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1760163002

Review URL: https://codereview.chromium.org/1760163002

1 files changed, 7 insertions, 0 deletions

diff --git a/gm/textblobmixedsizes.cpp b/gm/textblobmixedsizes.cpp
index 330d33f62c..86ab0ac8fb 100644
--- a/gm/textblobmixedsizes.cpp
+++ b/gm/textblobmixedsizes.cpp
@@ -73,6 +73,13 @@ protected:
 
         sk_tool_utils::add_to_text_blob(&builder, text, paint, 0, yOffset);
 
+        // Zero size.
+        paint.measureText(text, strlen(text), &bounds);
+        yOffset += bounds.height();
+        paint.setTextSize(0);
+
+        sk_tool_utils::add_to_text_blob(&builder, text, paint, 0, yOffset);
+
         // build
         fBlob.reset(builder.build());
     }