whitelist fallback typefaces

src/core/SkString.cpp

Index: src/core/SkString.cpp
diff --git a/src/core/SkString.cpp b/src/core/SkString.cpp
index d93f662da3d8bc0a80ca96903752bbcc3977ba1e..d75b2edaaea40eeb99897001252f8d3e772e8a9f 100644
--- a/src/core/SkString.cpp
+++ b/src/core/SkString.cpp
@@ -377,7 +377,7 @@ void SkString::set(const char text[], size_t len) {
         p[len] = 0;
         fRec->fLength = SkToU32(len);
     } else {
-        SkString tmp(text, len);
+        SkString tmp(text ? text : this->c_str(), len);

[bungeman-skia, 2015/08/28 21:09:57]

What is this for? If text is NULL here, shouldn't the len always be 0 or this
should fault?

[reed1, 2015/08/31 12:20:25]

+1 -- seems like its an error (assert?) to pass NULL w/ non-zero length

         this->swap(tmp);
     }
 }