pdfviewer: limit the characters we support in ToUnicode, to 0xffff

experimental/PdfViewer/SkPdfFont.cpp

 #include "SkPdfFont.h"
 
 #include "SkStream.h"
 #include "SkTypeface.h"
 #include "SkPdfNativeTokenizer.h"
 
 std::map<std::string, SkPdfStandardFontEntry>& getStandardFonts() {
     static std::map<std::string, SkPdfStandardFontEntry> gPdfStandardFonts;
 
     // TODO (edisonn): , vs - ? what does it mean?
@@ skipping 293 matching lines @@
 
     return new SkPdfMultiMasterFont(doc, dict);
 }
 
 static int skstoi(const SkPdfObject* str) {
     // TODO(edisonn): report err of it is not a (hex) string
     int ret = 0;
     for (unsigned int i = 0 ; i < str->len(); i++) {
         ret = (ret << 8) + ((unsigned char*)str->c_str())[i];
     }
-    return ret;
+    // TODO(edisonn): character larger than 0x0000ffff not supported right now.
+    return ret & 0x0000ffff;
 }
 
 #define tokenIsKeyword(token,keyword) (token.fType == kKeyword_TokenType && token.fKeywordLength==sizeof(keyword)-1 && strncmp(token.fKeyword, keyword, sizeof(keyword)-1) == 0)
 
 SkPdfToUnicode::SkPdfToUnicode(SkNativeParsedPDF* parsed, SkPdfStream* stream) : fParsed(parsed) {
     fCMapEncoding = NULL;
     fCMapEncodingFlag = NULL;
 
     if (stream) {
         // Since font will be cached, the font has to sit in the per doc allocator, not to be
@@ skipping 119 matching lines @@
 SkPdfEncoding* SkPdfEncoding::fromName(const char* name) {
     SkPdfEncoding* encoding = getStandardEncodings()[name];
 
 #ifdef PDF_TRACE
     if (encoding == NULL) {
         printf("Encoding not found: %s\n", name);
     }
 #endif
     return encoding;
 }