SkScalerContextRec::computeMatrices to return status.

src/ports/SkFontHost_mac.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTypes.h"  // Keep this before any #ifdef ...
 #if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
 
@@ skipping 789 matching lines @@
 
     CTFontRef ctFont = typeface->fFontRef.get();
     CFIndex numGlyphs = CTFontGetGlyphCount(ctFont);
     SkASSERT(numGlyphs >= 1 && numGlyphs <= 0xFFFF);
     fGlyphCount = SkToU16(numGlyphs);
 
     // CT on (at least) 10.9 will size color glyphs down from the requested size, but not up.
     // As a result, it is necessary to know the actual device size and request that.
     SkVector scale;
     SkMatrix skTransform;
-    fRec.computeMatrices(SkScalerContextRec::kVertical_PreMatrixScale, &scale, &skTransform,
-                         nullptr, nullptr, &fFUnitMatrix);
+    bool invertable = fRec.computeMatrices(SkScalerContextRec::kVertical_PreMatrixScale,
+                                           &scale, &skTransform, nullptr, nullptr, &fFUnitMatrix);
     fTransform = MatrixToCGAffineTransform(skTransform);
-    fInvTransform = CGAffineTransformInvert(fTransform);
+    // CGAffineTransformInvert documents that if the transform is non-invertible it will return the
+    // passed transform unchanged. It does so, but then also prints a message to stdout. Avoid this.
+    if (invertable) {
+        fInvTransform = CGAffineTransformInvert(fTransform);
+    } else {
+        fInvTransform = fTransform;
+    }
 
     // The transform contains everything except the requested text size.
     // Some properties, like 'trak', are based on the text size (before applying the matrix).
     CGFloat textSize = ScalarToCG(scale.y());
     fCTFont.reset(ctfont_create_exact_copy(ctFont, textSize, nullptr));
     fCGFont.reset(CTFontCopyGraphicsFont(fCTFont, nullptr));
 
     // The fUnitMatrix includes the text size (and em) as it is used to scale the raw font data.
     SkScalar emPerFUnit = SkScalarInvert(SkIntToScalar(CGFontGetUnitsPerEm(fCGFont)));
     fFUnitMatrix.preScale(emPerFUnit, -emPerFUnit);
@@ skipping 1787 matching lines @@
 
         return SkSafeRef(GetDefaultFace());
     }
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkFontMgr* SkFontMgr::Factory() { return new SkFontMgr_Mac; }
 
 #endif//defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)