Attachment 138492 Details for Bug 105674 – [PATCH v2] Fix PDFDoc::checkHeader() for PDFs smaller than 1 KiB

[patch] [PATCH v2] Fix PDFDoc::checkHeader() for PDFs smaller than 1 KiB

0001-Fix-PDFDoc-checkHeader-for-PDFs-smaller-than-1-KiB.patch (text/plain), 1.97 KB, created by Evangelos Foutras on 2018-04-02 13:47:07 UTC

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Creator: Evangelos Foutras

Created: 2018-04-02 13:47:07 UTC

Size: 1.97 KB

patch

obsolete

>From da7516bddb196774de4322b8a9e320b17018630b Mon Sep 17 00:00:00 2001
>From: Evangelos Foutras <evangelos@foutrelis.com>
>Date: Mon, 2 Apr 2018 16:09:34 +0300
>Subject: [PATCH v2] Fix PDFDoc::checkHeader() for PDFs smaller than 1 KiB
>
>The fix for bug 104502 made it so PDFDoc::checkHeader() would print a
>warning and return immediatelly if it encounters an EOF while reading
>the first 1024 bytes.
>
>Some PDF files can be smaller than 1024 bytes, for example those used
>by pdf2djvu's test suite. The latter would fail due to the unexpected
>warnings.
>
>Change the behavior of PDFDoc::checkHeader() when encountering an EOF
>so it processes the data it has read so far instead of aborting early.
>
>https://bugs.freedesktop.org/show_bug.cgi?id=105674
>---
> poppler/PDFDoc.cc | 21 ++++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
>diff --git a/poppler/PDFDoc.cc b/poppler/PDFDoc.cc
>index 6789c39f..656493ed 100644
>--- a/poppler/PDFDoc.cc
>+++ b/poppler/PDFDoc.cc
>@@ -410,23 +410,30 @@ void PDFDoc::checkHeader() {
>   char *tokptr;
>   int i;
>   int c;
>+  int bytesRead;
> 
>   pdfMajorVersion = 0;
>   pdfMinorVersion = 0;
>+
>+  // read up to headerSearchSize bytes from the beginning of the document
>   for (i = 0; i < headerSearchSize; ++i) {
>-    if ((c = str->getChar()) == EOF) {
>-      error(errSyntaxWarning, -1, "EOF while reading header (continuing anyway)");
>-      return;
>-    }
>+    c = str->getChar();
>+    if (c == EOF)
>+      break;
>     hdrBuf[i] = c;
>   }
>-  hdrBuf[headerSearchSize] = '\0';
>-  for (i = 0; i < headerSearchSize - 5; ++i) {
>+  bytesRead = i;
>+  hdrBuf[bytesRead] = '\0';
>+
>+  // find the start of the PDF header if it exists and parse the version
>+  bool headerFound = false;
>+  for (i = 0; i < bytesRead - 5; ++i) {
>     if (!strncmp(&hdrBuf[i], "%PDF-", 5)) {
>+      headerFound = true;
>       break;
>     }
>   }
>-  if (i >= headerSearchSize - 5) {
>+  if (!headerFound) {
>     error(errSyntaxWarning, -1, "May not be a PDF file (continuing anyway)");
>     return;
>   }
>-- 
>2.16.3
>

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