pdfviewer: more simple fixed to prevent crashes

experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.cpp

 
 #include "SkPdfNativeTokenizer.h"
 #include "SkPdfObject.h"
 #include "SkPdfConfig.h"
 
 #include "SkPdfStreamCommonDictionary_autogen.h"
 #include "SkPdfImageDictionary_autogen.h"
 
 // TODO(edisonn): perf!!!
 // there could be 0s between start and end! but not in the needle.
@@ skipping 107 matching lines @@
 
     while (start < end && !isPdfWhiteSpaceOrPdfDelimiter(*start)) {
         TRACE_TK(*start);
         start++;
     }
     return start;
 }
 
 // last elem has to be ]
 static const unsigned char* readArray(int level, const unsigned char* start, const unsigned char* end, SkPdfObject* array, SkPdfAllocator* allocator, SkNativeParsedPDF* doc) {
+    if (allocator == NULL) {
+        // TODO(edisonn): report/warning error
+        return end;
+    }
+
     TRACE_INDENT(level, "Array");
     while (start < end) {
         // skip white spaces
         start = skipPdfWhiteSpaces(level + 1, start, end);
 
         const unsigned char* endOfToken = endOfPdfToken(level + 1, start, end);
 
         if (endOfToken == start) {
             // TODO(edisonn): report error in pdf file (end of stream with ] for end of aray
             return start;
@@ skipping 63 matching lines @@
                         break;
 
                     case 'b':
                         // TODO(edisonn): any special meaning to backspace?
                         if (hasOut) { *out = kBackspace_PdfSpecial; }
                         out++;
                         in += 2;
                         break;
 
                     case 'f':
-                        *out = kFF_PdfWhiteSpace;
+                        if (hasOut) { *out = kFF_PdfWhiteSpace; }
                         out++;
                         in += 2;
                         break;
 
                     case kOpenedRoundBracket_PdfDelimiter:
                         if (hasOut) { *out = kOpenedRoundBracket_PdfDelimiter; }
                         out++;
                         in += 2;
                         break;
 
@@ skipping 464 matching lines @@
         inlineImage->addStream(start, (size_t)length);
     } else {
         // TODO(edisonn): report error in inline image stream (ID-EI) section
         // TODO(edisonn): based on filter, try to ignore a missing EI, and read data properly
         return end;
     }
     return endEI;
 }
 
 static const unsigned char* readDictionary(int level, const unsigned char* start, const unsigned char* end, SkPdfObject* dict, SkPdfAllocator* allocator, SkNativeParsedPDF* doc) {
+    if (allocator == NULL) {
+        // TODO(edisonn): report/warning error
+        return end;
+    }
     TRACE_INDENT(level, "Dictionary");
     SkPdfObject::makeEmptyDictionary(dict);
 
     start = skipPdfWhiteSpaces(level, start, end);
     SkPdfAllocator tmpStorage;  // keys will be stored in dict, we can free them immediately after set.
 
     while (start < end && *start == kNamed_PdfDelimiter) {
         SkPdfObject key;
         //*start = '\0';
         start++;
@@ skipping 353 matching lines @@
             SkPdfObject* obj = fAllocator->allocObject();
             fUncompressedStream = nextObject(0, fUncompressedStream, fUncompressedStreamEnd, obj, fAllocator, fDoc);
             // TODO(edisonn): perf maybe we should not expand abreviation like this
             inlineImage->set(inlineImageKeyAbbreviationExpand(key),
                              inlineImageValueAbbreviationExpand(obj));
         }
     }
     // TODO(edisonn): report end of data with inline image without an EI
     return inlineImage;
 }