From 1b47b1a78da9c395dc7731006e8e5e59ba898022 Mon Sep 17 00:00:00 2001
From: Adrian Johnson <ajohnson@redneon.com>
Date: Thu, 19 Mar 2009 22:34:23 +1030
Subject: [PATCH] Fix bug in cairo backend with nested masks

The previous smask was not restored after a q/Q pair or form xobject.
---
 poppler/CairoOutputDev.cc |   18 +++++++++++++++++-
 poppler/CairoOutputDev.h  |    5 +++++
 2 files changed, 22 insertions(+), 1 deletions(-)

diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index 822d66d..fd93e05 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -132,6 +132,7 @@ CairoOutputDev::CairoOutputDev() {
   t3_glyph_has_bbox = gFalse;
 
   groupColorSpaceStack = NULL;
+  maskStack = NULL;
   group = NULL;
   mask = NULL;
   shape = NULL;
@@ -242,6 +243,11 @@ void CairoOutputDev::saveState(GfxState *state) {
   cairo_save (cairo);
   if (cairo_shape)
       cairo_save (cairo_shape);
+
+  MaskStack *ms = new MaskStack;
+  ms->mask = cairo_pattern_reference(mask);
+  ms->next = maskStack;
+  maskStack = ms;
 }
 
 void CairoOutputDev::restoreState(GfxState *state) {
@@ -256,6 +262,14 @@ void CairoOutputDev::restoreState(GfxState *state) {
   updateStrokeColor(state);
   updateFillOpacity(state);
   updateStrokeOpacity(state);
+
+  MaskStack* ms = maskStack;
+  if (mask)
+    cairo_pattern_destroy(mask);
+
+  mask = ms->mask;
+  maskStack = ms->next;
+  delete ms;
 }
 
 void CairoOutputDev::updateAll(GfxState *state) {
@@ -1024,7 +1038,9 @@ void CairoOutputDev::popTransparencyGroup() {
 
 
 void CairoOutputDev::clearSoftMask(GfxState * /*state*/) {
-  //XXX: should we be doing anything here?
+  if (mask)
+    cairo_pattern_destroy(mask);
+  mask = NULL;
 }
 
 void CairoOutputDev::drawImageMask(GfxState *state, Object *ref, Stream *str,
diff --git a/poppler/CairoOutputDev.h b/poppler/CairoOutputDev.h
index 1e410c1..5ec2bf0 100644
--- a/poppler/CairoOutputDev.h
+++ b/poppler/CairoOutputDev.h
@@ -271,6 +271,11 @@ protected:
     GfxColorSpace *cs;
     struct ColorSpaceStack *next;
   } * groupColorSpaceStack;
+
+  struct MaskStack {
+      cairo_pattern_t *mask;
+      struct MaskStack *next;
+  } *maskStack;
 };
 
 //------------------------------------------------------------------------
-- 
1.5.6.3