Make inline image token exactly contain the image data

Do not include the trailing EI, and handle cases where EI is not
preceded by a delimiter. Such cases have been seen in the wild.

3 files changed, 7 insertions, 25 deletions

diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc
index de5d56b3..a3a4d61d 100644
--- a/libqpdf/QPDFObjectHandle.cc
+++ b/libqpdf/QPDFObjectHandle.cc
@@ -1570,16 +1570,7 @@ QPDFObjectHandle::parseContentStream_data(
             }
             else
             {
-                // Skip back over EI
-                input->seek(-2, SEEK_CUR);
-                std::string inline_image = t.getRawValue();
-                for (int i = 0; i < 3; ++i)
-                {
-                    if (inline_image.length() > 0)
-                    {
-                        inline_image.erase(inline_image.length() - 1);
-                    }
-                }
+                std::string inline_image = t.getValue();
                 QTC::TC("qpdf", "QPDFObjectHandle inline image token");
                 callbacks->handleObject(
                     QPDFObjectHandle::newInlineImage(inline_image));
diff --git a/libqpdf/QPDFPageObjectHelper.cc b/libqpdf/QPDFPageObjectHelper.cc
index caaff853..e72b4c70 100644
--- a/libqpdf/QPDFPageObjectHelper.cc
+++ b/libqpdf/QPDFPageObjectHelper.cc
@@ -228,10 +228,6 @@ InlineImageTracker::handleToken(QPDFTokenizer::Token const& token)
         {
             std::string image_data(token.getValue());
             size_t len = image_data.length();
-            // The token ends with delimiter followed by EI, so it
-            // will always be at least 3 bytes long. We want to
-            // exclude the EI and preceding delimiter.
-            len = (len >= 3 ? len - 3 : 0);
             if (len >= this->min_size)
             {
                 QTC::TC("qpdf", "QPDFPageObjectHelper externalize inline image");
@@ -256,14 +252,18 @@ InlineImageTracker::handleToken(QPDFTokenizer::Token const& token)
                 QTC::TC("qpdf", "QPDFPageObjectHelper keep inline image");
                 write(bi_str);
                 writeToken(token);
+                state = st_top;
             }
-            state = st_top;
         }
         else if (token == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "ID"))
         {
             bi_str += token.getValue();
             dict_str += " >>";
         }
+        else if (token == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "EI"))
+        {
+            state = st_top;
+        }
         else
         {
             bi_str += token.getValue();
diff --git a/libqpdf/QPDFTokenizer.cc b/libqpdf/QPDFTokenizer.cc
index 2671fcbb..80fcf347 100644
--- a/libqpdf/QPDFTokenizer.cc
+++ b/libqpdf/QPDFTokenizer.cc
@@ -73,15 +73,6 @@ QPDFWordTokenFinder::check()
         // beginning of the input.
         return false;
     }
-    is->seek(token_start - 1, SEEK_SET);
-    char prev;
-    bool prev_okay = ((is->read(&prev, 1) == 1) && is_delimiter(prev));
-    is->seek(pos, SEEK_SET);
-    if (! prev_okay)
-    {
-        QTC::TC("qpdf", "QPDFTokenizer finder word not preceded by delimiter");
-        return false;
-    }
     return true;
 }
 
@@ -724,7 +715,7 @@ QPDFTokenizer::findEI(PointerHolder<InputSource> input)
         {
             break;
         }
-        this->m->inline_image_bytes = input->tell() - pos;
+        this->m->inline_image_bytes = input->tell() - pos - 2;
 
         QPDFTokenizer check;
         bool found_bad = false;