From 634fa34f946fb3d48736917102a1e5be583a3fc8 Mon Sep 17 00:00:00 2001
From: Robin Watts <robin.watts@artifex.com>
Date: Mon, 2 Jan 2012 18:25:10 +0000
Subject: Fix bug 692593 - solve crash due to inappropriately sized shape
 plane.

When starting to tile, create a shape plane if one exists.

When finishing tiling, plot the shape plane back too.

This solves the SEGVs. Something isn't quite right with the blending
colours on part of this file though.
---
 draw/draw_device.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 52 insertions(+), 8 deletions(-)

diff --git a/draw/draw_device.c b/draw/draw_device.c
index 2634c4f8..5583c30e 100644
--- a/draw/draw_device.c
+++ b/draw/draw_device.c
@@ -1461,8 +1461,10 @@ fz_draw_begin_tile(fz_device *devp, fz_rect area, fz_rect view, float xstep, flo
 {
 	fz_draw_device *dev = devp->user;
 	fz_colorspace *model = dev->dest->colorspace;
-	fz_pixmap *dest;
+	fz_pixmap *dest = NULL;
+	fz_pixmap *shape = dev->shape;
 	fz_bbox bbox;
+	fz_context *ctx = dev->ctx;
 
 	/* area, view, xstep, ystep are in pattern space */
 	/* ctm maps from pattern space to device space */
@@ -1482,7 +1484,20 @@ fz_draw_begin_tile(fz_device *devp, fz_rect area, fz_rect view, float xstep, flo
 	dest = fz_new_pixmap_with_rect(dev->ctx, model, bbox);
 	/* FIXME: See note #1 */
 	fz_clear_pixmap(dest);
-
+	if (shape)
+	{
+		fz_var(shape);
+		fz_try(ctx)
+		{
+			shape = fz_new_pixmap_with_rect(dev->ctx, NULL, bbox);
+			fz_clear_pixmap(shape);
+		}
+		fz_catch(ctx)
+		{
+			fz_drop_pixmap(ctx, dest);
+			fz_rethrow(ctx);
+		}
+	}
 	dev->stack[dev->top].scissor = dev->scissor;
 	dev->stack[dev->top].dest = dev->dest;
 	dev->stack[dev->top].shape = dev->shape;
@@ -1499,6 +1514,7 @@ fz_draw_begin_tile(fz_device *devp, fz_rect area, fz_rect view, float xstep, flo
 
 	dev->scissor = bbox;
 	dev->dest = dest;
+	dev->shape = shape;
 }
 
 static void
@@ -1506,26 +1522,24 @@ fz_draw_end_tile(fz_device *devp)
 {
 	fz_draw_device *dev = devp->user;
 	fz_pixmap *tile = dev->dest;
+	fz_pixmap *tileshape = dev->shape;
 	float xstep, ystep;
-	fz_matrix ctm, ttm;
+	fz_matrix ctm, ttm, shapectm;
 	fz_rect area;
 	int x0, y0, x1, y1, x, y;
 
 	if (dev->top > 0)
 	{
 		dev->top--;
-#ifdef DUMP_GROUP_BLENDS
-		dump_spaces(dev->top, "Tile end\n");
-#endif
 		xstep = dev->stack[dev->top].xstep;
 		ystep = dev->stack[dev->top].ystep;
 		area = dev->stack[dev->top].area;
 		ctm = dev->stack[dev->top].ctm;
 		dev->scissor = dev->stack[dev->top].scissor;
 		dev->dest = dev->stack[dev->top].dest;
+		dev->shape = dev->stack[dev->top].shape;
 		dev->blendmode = dev->stack[dev->top].blendmode;
 
-
 		x0 = floorf(area.x0 / xstep);
 		y0 = floorf(area.y0 / ystep);
 		x1 = ceilf(area.x1 / xstep);
@@ -1533,6 +1547,22 @@ fz_draw_end_tile(fz_device *devp)
 
 		ctm.e = tile->x;
 		ctm.f = tile->y;
+		if (tileshape)
+		{
+			shapectm = ctm;
+			shapectm.e = tileshape->x;
+			shapectm.f = tileshape->y;
+		}
+
+#ifdef DUMP_GROUP_BLENDS
+		dump_spaces(dev->top, "");
+		fz_dump_blend(dev->ctx, tile, "Tiling ");
+		if (tileshape)
+			fz_dump_blend(dev->ctx, tileshape, "/");
+		fz_dump_blend(dev->ctx, dev->dest, " onto ");
+		if (dev->shape)
+			fz_dump_blend(dev->ctx, dev->shape, "/");
+#endif
 
 		for (y = y0; y < y1; y++)
 		{
@@ -1542,10 +1572,24 @@ fz_draw_end_tile(fz_device *devp)
 				tile->x = ttm.e;
 				tile->y = ttm.f;
 				fz_paint_pixmap_with_rect(dev->dest, tile, 255, dev->scissor);
+				if (tileshape)
+				{
+					ttm = fz_concat(fz_translate(x * xstep, y * ystep), shapectm);
+					tileshape->x = ttm.e;
+					tileshape->y = ttm.f;
+					fz_paint_pixmap_with_rect(dev->shape, tileshape, 255, dev->scissor);
+				}
 			}
 		}
 
 		fz_drop_pixmap(dev->ctx, tile);
+		fz_drop_pixmap(dev->ctx, tileshape);
+#ifdef DUMP_GROUP_BLENDS
+		fz_dump_blend(dev->ctx, dev->dest, " to get ");
+		if (dev->shape)
+			fz_dump_blend(dev->ctx, dev->shape, "/");
+		printf("\n");
+#endif
 	}
 
 	if (dev->blendmode & FZ_BLEND_KNOCKOUT)
@@ -1557,7 +1601,7 @@ fz_draw_free_user(fz_device *devp)
 {
 	fz_draw_device *dev = devp->user;
 	fz_context *ctx = dev->ctx;
-	/* TODO: pop and free the stacks */
+	/* pop and free the stacks */
 	if (dev->top > 0)
 	{
 		fz_warn(ctx, "items left on stack in draw device: %d", dev->top);
-- 
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