Bug 1621502 - fix lengthAdjust when applied to vertical text r=jfkthame

Differential Revision: https://phabricator.services.mozilla.com/D199797

layout/svg/SVGTextFrame.cpp

@@ -718,16 +718,16 @@ gfxMatrix TextRenderedRun::GetTransformFromUserSpaceForPainting(
   // Rotation due to rotate="" or a <textPath>.
   m.PreRotate(mRotate);
 
-  m.PreScale(mLengthAdjustScaleFactor, 1.0);
-
-  // Translation to get the text frame in the right place.
+  // Scale for textLength="" and translate to get the text frame
+  // to the right place.
   nsPoint t;
-
   if (IsVertical()) {
+    m.PreScale(1.0, mLengthAdjustScaleFactor);
     t = nsPoint(-mBaseline, IsRightToLeft()
                                 ? -mFrame->GetRect().height + aVisIEndEdge
                                 : -aVisIStartEdge);
   } else {
+    m.PreScale(mLengthAdjustScaleFactor, 1.0);
     t = nsPoint(IsRightToLeft() ? -mFrame->GetRect().width + aVisIEndEdge
                                 : -aVisIStartEdge,
                 -mBaseline);
@@ -756,15 +756,16 @@ gfxMatrix TextRenderedRun::GetTransformFromRunUserSpaceToUserSpace(
   // Rotation due to rotate="" or a <textPath>.
   m.PreRotate(mRotate);
 
-  // Scale due to textLength="".
-  m.PreScale(mLengthAdjustScaleFactor, 1.0);
+  // Scale for textLength="" and translate to get the text frame
+  // to the right place.
 
-  // Translation to get the text frame in the right place.
   nsPoint t;
   if (IsVertical()) {
+    m.PreScale(1.0, mLengthAdjustScaleFactor);
     t = nsPoint(-mBaseline,
                 IsRightToLeft() ? -mFrame->GetRect().height + start + end : 0);
   } else {
+    m.PreScale(mLengthAdjustScaleFactor, 1.0);
     t = nsPoint(IsRightToLeft() ? -mFrame->GetRect().width + start + end : 0,
                 -mBaseline);
   }
@@ -869,6 +870,12 @@ SVGBBox TextRenderedRun::GetRunUserSpaceRect(nsPresContext* aContext,
               fillInAppUnits.height),
       aContext);
 
+  if (vertical) {
+    fill.Scale(1.0, mLengthAdjustScaleFactor);
+  } else {
+    fill.Scale(mLengthAdjustScaleFactor, 1.0);
+  }
+
   // Scale the rectangle up due to any mFontSizeScaleFactor.
   fill.Scale(1.0 / mFontSizeScaleFactor);
 

testing/web-platform/tests/svg/text/reftests/green-100x100.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg">
+  <rect width="100" height="100" fill="green"/>
+</svg>

testing/web-platform/tests/svg/text/reftests/lengthAdjust-vertical.svg

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:h="http://www.w3.org/1999/xhtml">
+  <metadata>
+    <title>lengthAdjust="spacingAndGlyphs" should work on vertical text</title>
+    <h:link rel="help" href="https://www.w3.org/TR/SVG2/text.html#TextElementLengthAdjustAttribute"/>
+    <h:link rel="match" href="green-100x100.svg"/>
+    <h:link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
+  </metadata>
+  <style>
+    text {
+      font: 25px/1 Ahem;
+    }
+  </style>
+  <rect fill="green" width="100" height="100"/>
+  <text x="50" y="10" fill="red" textLength="80" lengthAdjust="spacingAndGlyphs" font-family="Ahem" style="writing-mode: vertical-lr">
+    XX
+  </text>
+  <rect fill="green" x="37" y="9" width="26" height="82"/>
+</svg>