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From 718d428984e3a84fda521c0f5e6d975c7390af2b Mon Sep 17 00:00:00 2001
From: Marek Kasik <mkasik@redhat.com>
Date: Fri, 6 Apr 2018 15:06:46 +0200
Subject: [PATCH] cairo: Fix tiling patterns when pattern cell is too far

Rendering of tiling pattern which has pattern matrix moving pattern cell
far away can fail on allocation of memory. This commit solves the issue by
modifying of cairo pattern matrix so that its offset is closer to the path
filled by the pattern.

https://bugs.freedesktop.org/show_bug.cgi?id=105905
---
 poppler/CairoOutputDev.cc | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index 631ab27b..b2e730bf 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -915,6 +915,8 @@ GBool CairoOutputDev::tilingPatternFill(GfxState *state, Gfx *gfxA, Catalog *cat
   StrokePathClip *strokePathTmp;
   GBool adjusted_stroke_width_tmp;
   cairo_pattern_t *maskTmp;
+  double xoffset, yoffset;
+  double det;
 
   width = bbox[2] - bbox[0];
   height = bbox[3] - bbox[1];
@@ -976,6 +978,15 @@ GBool CairoOutputDev::tilingPatternFill(GfxState *state, Gfx *gfxA, Catalog *cat
   if (cairo_pattern_status (pattern))
     return gFalse;
 
+  det = pmat[0] * pmat[3] - pmat[1] * pmat[2];
+  if (fabs(det) < 0.000001)
+    return gFalse;
+
+  xoffset = round ((pmat[3] * pmat[4] - pmat[2] * pmat[5]) / (xStep * det));
+  yoffset = - round ((pmat[1] * pmat[4] - pmat[0] * pmat[5]) / (yStep * det));
+  pattern_matrix.x0 -= xoffset * pattern_matrix.xx * xStep + yoffset * pattern_matrix.xy * yStep;
+  pattern_matrix.y0 -= xoffset * pattern_matrix.yx * xStep + yoffset * pattern_matrix.yy * yStep;
+
   state->getUserClipBBox(&xMin, &yMin, &xMax, &yMax);
   cairo_rectangle (cairo, xMin, yMin, xMax - xMin, yMax - yMin);
 
-- 
2.14.3