Attachment 121586 Details for Bug 87637 – reconstruct xref table if xrefs are missing but needed

[patch] reconstruct xref table if xrefs are missing but needed

87637.patch (text/plain), 2.76 KB, created by Thomas Freitag on 2016-02-08 13:47:56 UTC

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Creator: Thomas Freitag

Created: 2016-02-08 13:47:56 UTC

Size: 2.76 KB

patch

obsolete

>diff --git a/poppler/PDFDoc.cc b/poppler/PDFDoc.cc
>index 8287060..6467d0b 100644
>--- a/poppler/PDFDoc.cc
>+++ b/poppler/PDFDoc.cc
>@@ -1478,7 +1478,7 @@ void PDFDoc::markObject (Object* obj, XRef *xRef, XRef *countRef, Guint numOffse
>     case objRef:
>       {
>         if (obj->getRef().num + (int) numOffset >= xRef->getNumObjects() || xRef->getEntry(obj->getRef().num + numOffset)->type == xrefEntryFree) {
>-          if (getXRef()->getEntry(obj->getRef().num)->type == xrefEntryFree) {
>+          if (getXRef()->getEntryAndReconstruct(obj->getRef().num)->type == xrefEntryFree) {
>             return;  // already marked as free => should be replaced
>           }
>           xRef->add(obj->getRef().num + numOffset, obj->getRef().gen, 0, gTrue);
>diff --git a/poppler/XRef.cc b/poppler/XRef.cc
>index 1bbbdc5..c053b26 100644
>--- a/poppler/XRef.cc
>+++ b/poppler/XRef.cc
>@@ -1639,6 +1639,52 @@ XRefEntry *XRef::getEntry(int i, GBool complainIfMissing)
>   return &entries[i];
> }
> 
>+XRefEntry *XRef::getEntryAndReconstruct(int i, GBool complainIfMissing)
>+{
>+  if (i >= size || entries[i].type == xrefEntryNone) {
>+
>+    if ((!xRefStream) && mainXRefEntriesOffset) {
>+      if (!parseEntry(mainXRefEntriesOffset + 20*i, &entries[i])) {
>+        error(errSyntaxError, -1, "Failed to parse XRef entry [{0:d}].", i);
>+      }
>+    } else {
>+      // Read XRef tables until the entry we're looking for is found
>+      readXRefUntil(i);
>+      
>+      // We might have reconstructed the xref
>+      // Check again i is in bounds
>+      if (unlikely(i >= size)) {
>+        static XRefEntry dummy;
>+        dummy.offset = 0;
>+        dummy.gen = -1;
>+        dummy.type = xrefEntryNone;
>+        dummy.flags = 0;
>+        return &dummy;
>+      }
>+
>+      if (entries[i].type == xrefEntryNone) {
>+        GBool wasReconstructed = false;
>+        if (!(ok = constructXRef(&wasReconstructed))) {
>+            errCode = errDamaged;
>+        } else {
>+	  for (int j=0; j < size; j++) {
>+            if (entries[j].type == xrefEntryNone) {
>+              entries[j].type = xrefEntryFree;
>+            }
>+	  }
>+	}
>+      }
>+      if (entries[i].type == xrefEntryFree) {
>+        if (complainIfMissing) {
>+          error(errSyntaxError, -1, "Invalid XRef entry");
>+        }
>+      }
>+    }
>+  }
>+
>+  return &entries[i];
>+}
>+
> // Recursively sets the Unencrypted flag in all referenced xref entries
> void XRef::markUnencrypted(Object *obj) {
>   Object obj1;
>diff --git a/poppler/XRef.h b/poppler/XRef.h
>index 70065d8..75b7e2e 100644
>--- a/poppler/XRef.h
>+++ b/poppler/XRef.h
>@@ -173,6 +173,7 @@ public:
> 
>   // Direct access.
>   XRefEntry *getEntry(int i, GBool complainIfMissing = gTrue);
>+  XRefEntry *getEntryAndReconstruct(int i, GBool complainIfMissing = gTrue);
>   Object *getTrailerDict() { return &trailerDict; }
> 
>   // Write access

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Attachments on bug 87637: 111220 | 111850 | 113165 | 113535 | 113803 | 113837 | 118096 | 121505 | 121536 | 121586 | 122326

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