Fix searching for end of inline (EI) images with ASCII85Decode filters (bug 1077808)

This patch changes searching for the end of inline image streams to rely on the EOD marker for the filters: ASCII85Decode and ASCIIHexDecode.

src/core/parser.js

@@ -126,31 +126,14 @@ var Parser = (function ParserClosure() {
       // simple object
       return buf1;
     },
-    makeInlineImage: function Parser_makeInlineImage(cipherTransform) {
+    /**
-      var lexer = this.lexer;
+     * Find the end of the stream by searching for the /EI\s/.
-      var stream = lexer.stream;
+     * @returns {number} The inline stream length.
-
+     */
-      // parse dictionary
+    findDefaultInlineStreamEnd:
-      var dict = new Dict(null);
+        function Parser_findDefaultInlineStreamEnd(stream) {
-      while (!isCmd(this.buf1, 'ID') && !isEOF(this.buf1)) {
+      var E = 0x45, I = 0x49, SPACE = 0x20, LF = 0xA, CR = 0xD;
-        if (!isName(this.buf1)) {
+      var startPos = stream.pos, state = 0, ch, i, n, followingBytes;
-          error('Dictionary key must be a name object');
-        }
-
-        var key = this.buf1.name;
-        this.shift();
-        if (isEOF(this.buf1)) {
-          break;
-        }
-        dict.set(key, this.getObj(cipherTransform));
-      }
-
-      // parse image stream
-      var startPos = stream.pos;
-
-      // searching for the /EI\s/
-      var state = 0, ch, i, ii;
-      var E = 0x45, I = 0x49, SPACE = 0x20, NL = 0xA, CR = 0xD;
       while ((ch = stream.getByte()) !== -1) {
         if (state === 0) {
           state = (ch === E) ? 1 : 0;
@@ -158,13 +141,13 @@ var Parser = (function ParserClosure() {
           state = (ch === I) ? 2 : 0;
         } else {
           assert(state === 2);
-          if (ch === SPACE || ch === NL || ch === CR) {
+          if (ch === SPACE || ch === LF || ch === CR) {
             // Let's check the next five bytes are ASCII... just be sure.
-            var n = 5;
+            n = 5;
-            var followingBytes = stream.peekBytes(n);
+            followingBytes = stream.peekBytes(n);
             for (i = 0; i < n; i++) {
               ch = followingBytes[i];
-              if (ch !== NL && ch !== CR && (ch < SPACE || ch > 0x7F)) {
+              if (ch !== LF && ch !== CR && (ch < SPACE || ch > 0x7F)) {
                 // Not a LF, CR, SPACE or any visible ASCII character, i.e.
                 // it's binary stuff. Resetting the state.
                 state = 0;
@@ -172,18 +155,116 @@ var Parser = (function ParserClosure() {
               }
             }
             if (state === 2) {
-              break;  // finished!
+              break;  // Finished!
             }
           } else {
             state = 0;
           }
         }
       }
+      return ((stream.pos - 4) - startPos);
+    },
+    /**
+     * Find the EOD (end-of-data) marker '~>' (i.e. TILDE + GT) of the stream.
+     * @returns {number} The inline stream length.
+     */
+    findASCII85DecodeInlineStreamEnd:
+        function Parser_findASCII85DecodeInlineStreamEnd(stream) {
+      var TILDE = 0x7E, GT = 0x3E;
+      var startPos = stream.pos, ch, length;
+      while ((ch = stream.getByte()) !== -1) {
+        if (ch === TILDE && stream.peekByte() === GT) {
+          stream.skip();
+          break;
+        }
+      }
+      length = stream.pos - startPos;
+      if (ch === -1) {
+        warn('Inline ASCII85Decode image stream: ' +
+             'EOD marker not found, searching for /EI/ instead.');
+        stream.skip(-length); // Reset the stream position.
+        return this.findDefaultInlineStreamEnd(stream);
+      }
+      this.inlineStreamSkipEI(stream);
+      return length;
+    },
+    /**
+     * Find the EOD (end-of-data) marker '>' (i.e. GT) of the stream.
+     * @returns {number} The inline stream length.
+     */
+    findASCIIHexDecodeInlineStreamEnd:
+        function Parser_findASCIIHexDecodeInlineStreamEnd(stream) {
+      var GT = 0x3E;
+      var startPos = stream.pos, ch, length;
+      while ((ch = stream.getByte()) !== -1) {
+        if (ch === GT) {
+          break;
+        }
+      }
+      length = stream.pos - startPos;
+      if (ch === -1) {
+        warn('Inline ASCIIHexDecode image stream: ' +
+             'EOD marker not found, searching for /EI/ instead.');
+        stream.skip(-length); // Reset the stream position.
+        return this.findDefaultInlineStreamEnd(stream);
+      }
+      this.inlineStreamSkipEI(stream);
+      return length;
+    },
+    /**
+     * Skip over the /EI/ for streams where we search for an EOD marker.
+     */
+    inlineStreamSkipEI: function Parser_inlineStreamSkipEI(stream) {
+      var E = 0x45, I = 0x49;
+      var state = 0, ch;
+      while ((ch = stream.getByte()) !== -1) {
+        if (state === 0) {
+          state = (ch === E) ? 1 : 0;
+        } else if (state === 1) {
+          state = (ch === I) ? 2 : 0;
+        } else if (state === 2) {
+          break;
+        }
+      }
+    },
+    makeInlineImage: function Parser_makeInlineImage(cipherTransform) {
+      var lexer = this.lexer;
+      var stream = lexer.stream;
 
-      var length = (stream.pos - 4) - startPos;
+      // Parse dictionary.
+      var dict = new Dict(null);
+      while (!isCmd(this.buf1, 'ID') && !isEOF(this.buf1)) {
+        if (!isName(this.buf1)) {
+          error('Dictionary key must be a name object');
+        }
+        var key = this.buf1.name;
+        this.shift();
+        if (isEOF(this.buf1)) {
+          break;
+        }
+        dict.set(key, this.getObj(cipherTransform));
+      }
+
+      // Extract the name of the first (i.e. the current) image filter.
+      var filter = this.fetchIfRef(dict.get('Filter', 'F')), filterName;
+      if (isName(filter)) {
+        filterName = filter.name;
+      } else if (isArray(filter) && isName(filter[0])) {
+        filterName = filter[0].name;
+      }
+
+      // Parse image stream.
+      var startPos = stream.pos, length, i, ii;
+      if (filterName === 'ASCII85Decide' || filterName === 'A85') {
+        length = this.findASCII85DecodeInlineStreamEnd(stream);
+      } else if (filterName === 'ASCIIHexDecode' || filterName === 'AHx') {
+        length = this.findASCIIHexDecodeInlineStreamEnd(stream);
+      } else {
+        length = this.findDefaultInlineStreamEnd(stream);
+      }
       var imageStream = stream.makeSubStream(startPos, length, dict);
 
-      // cache all images below the MAX_LENGTH_TO_CACHE threshold by their
+      // Cache all images below the MAX_LENGTH_TO_CACHE threshold by their
       // adler32 checksum.
       var adler32;
       if (length < MAX_LENGTH_TO_CACHE) {
@@ -193,7 +274,7 @@ var Parser = (function ParserClosure() {
         var a = 1;
         var b = 0;
         for (i = 0, ii = imageBytes.length; i < ii; ++i) {
-          // no modulo required in the loop if imageBytes.length < 5552
+          // No modulo required in the loop if imageBytes.length < 5552.
           a += imageBytes[i] & 0xff;
           b += a;
         }

test/pdfs/bug1077808.pdf.link

@@ -0,0 +1 @@
+https://bug1077808.bugzilla.mozilla.org/attachment.cgi?id=8499998

test/test_manifest.json

@@ -1524,6 +1524,15 @@
       "type": "eq",
       "about": "Type3 font with negative HScale and font size"
     },
+    {  "id": "bug1077808",
+       "file": "pdfs/bug1077808.pdf",
+       "md5": "4a4bfc27e3fafe2f74e7a4a4cd04b8dc",
+       "rounds": 1,
+       "lastPage": 1,
+       "link": true,
+       "type": "eq",
+       "about": "Inline image with ASCII85Decode filter."
+    },
     {  "id": "bug1108753",
        "file": "pdfs/bug1108753.pdf",
        "md5": "a7aaf92d55b4602afb0ca3d75198b56b",