Attachment 122373 Details for Bug 92482 – implement sanity check for linearization usage

[patch] implement sanity check for linearization usage

92482.patch (text/plain), 2.39 KB, created by Thomas Freitag on 2016-03-17 12:17:06 UTC

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Creator: Thomas Freitag

Created: 2016-03-17 12:17:06 UTC

Size: 2.39 KB

patch

obsolete

>diff --git a/poppler/PDFDoc.cc b/poppler/PDFDoc.cc
>index f052772..7e3e338 100644
>--- a/poppler/PDFDoc.cc
>+++ b/poppler/PDFDoc.cc
>@@ -544,10 +544,50 @@ Linearization *PDFDoc::getLinearization()
> {
>   if (!linearization) {
>     linearization = new Linearization(str);
>+    linearizationState = 0;
>   }
>   return linearization;
> }
> 
>+GBool PDFDoc::checkLinearization() {
>+  if (linearization == NULL) 
>+    return gFalse;
>+  if (linearizationState == 1)
>+    return gTrue;
>+  if (linearizationState == 2)
>+    return gFalse;
>+  if (!hints) {
>+    hints = new Hints(str, linearization, getXRef(), secHdlr);
>+  }
>+  for (int page = 1; page <= linearization->getNumPages(); page++) {
>+    Object obj;
>+    Ref pageRef;
>+
>+    pageRef.num = hints->getPageObjectNum(page);
>+    if (!pageRef.num) {
>+      linearizationState = 2;
>+      return gFalse;
>+    }
>+
>+    // check for bogus ref - this can happen in corrupted PDF files
>+    if (pageRef.num < 0 || pageRef.num >= xref->getNumObjects()) {
>+      linearizationState = 2;
>+      return gFalse;
>+    }
>+
>+    pageRef.gen = xref->getEntry(pageRef.num)->gen;
>+    xref->fetch(pageRef.num, pageRef.gen, &obj);
>+    if (!obj.isDict("Page")) {
>+      obj.free();
>+      linearizationState = 2;
>+      return gFalse;
>+    }
>+    obj.free();
>+  }
>+  linearizationState = 1;
>+  return gTrue;
>+}
>+
> GBool PDFDoc::isLinearized(GBool tryingToReconstruct) {
>   if ((str->getLength()) &&
>       (getLinearization()->getLength() == str->getLength()))
>@@ -1963,7 +2003,7 @@ Page *PDFDoc::getPage(int page)
> {
>   if ((page < 1) || page > getNumPages()) return NULL;
> 
>-  if (isLinearized()) {
>+  if (isLinearized() && checkLinearization()) {
>     pdfdocLocker();
>     if (!pageCache) {
>       pageCache = (Page **) gmallocn(getNumPages(), sizeof(Page *));
>diff --git a/poppler/PDFDoc.h b/poppler/PDFDoc.h
>index 0bb15c4..052ca77 100644
>--- a/poppler/PDFDoc.h
>+++ b/poppler/PDFDoc.h
>@@ -111,6 +111,7 @@ public:
> 
>   // Get the linearization table.
>   Linearization *getLinearization();
>+  GBool checkLinearization();
> 
>   // Get the xref table.
>   XRef *getXRef() { return xref; }
>@@ -324,6 +325,10 @@ private:
>   int pdfMajorVersion;
>   int pdfMinorVersion;
>   Linearization *linearization;
>+  // linearizationState = 0: unchecked
>+  // linearizationState = 1: checked and valid
>+  // linearizationState = 2: checked and invalid
>+  int linearizationState;
>   XRef *xref;
>   SecurityHandler *secHdlr;
>   Catalog *catalog;

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Attachments on bug 92482: 118906 | 122277 | 122373

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