From d5d29075bdbb7f412fa6dc182573da18fd81af54 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 23 Oct 2008 15:24:13 +0100
Subject: [PATCH] [gstate] Allocate temporary variable for backend_to_user
 transform.

_cairo_gstate_backend_to_user_rectangle() requires that its input
arguments are non-NULL and describe the input rectangle to be transformed.
However, we were passing through output parameters from the public API
which were allowed to be NULL. So we need to allocate temporary variables
in which to compute the output rectangle, but only copy them as required.
---
 src/cairo-gstate.c | 81 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 56 insertions(+), 25 deletions(-)

diff --git a/src/cairo-gstate.c b/src/cairo-gstate.c
index 00f498e03..e1b4693c2 100644
--- a/src/cairo-gstate.c
+++ b/src/cairo-gstate.c
@@ -785,12 +785,25 @@ _cairo_gstate_path_extents (cairo_gstate_t     *gstate,
 			    double *x2, double *y2)
 {
     cairo_status_t status;
+    double px1, py1, px2, py2;
 
-    status = _cairo_path_fixed_bounds (path, x1, y1, x2, y2, gstate->tolerance);
+    status = _cairo_path_fixed_bounds (path,
+				       &px1, &py1, &px2, &py2,
+				       gstate->tolerance);
     if (status)
 	return status;
 
-    _cairo_gstate_backend_to_user_rectangle (gstate, x1, y1, x2, y2, NULL);
+    _cairo_gstate_backend_to_user_rectangle (gstate,
+					     &px1, &py1, &px2, &py2,
+					     NULL);
+    if (x1)
+	*x1 = px1;
+    if (y1)
+	*y1 = py1;
+    if (x2)
+	*x2 = px2;
+    if (y2)
+	*y2 = py2;
 
     return CAIRO_STATUS_SUCCESS;
 }
@@ -1083,18 +1096,26 @@ _cairo_gstate_traps_extents_to_user_rectangle (cairo_gstate_t	  *gstate,
 	if (y2)
 	    *y2 = 0.0;
     } else {
+	double px1, py1, px2, py2;
+
 	_cairo_traps_extents (traps, &extents);
 
-	if (x1)
-	    *x1 = _cairo_fixed_to_double (extents.p1.x);
-	if (y1)
-	    *y1 = _cairo_fixed_to_double (extents.p1.y);
-	if (x2)
-	    *x2 = _cairo_fixed_to_double (extents.p2.x);
-	if (y2)
-	    *y2 = _cairo_fixed_to_double (extents.p2.y);
+	px1 = _cairo_fixed_to_double (extents.p1.x);
+	py1 = _cairo_fixed_to_double (extents.p1.y);
+	px2 = _cairo_fixed_to_double (extents.p2.x);
+	py2 = _cairo_fixed_to_double (extents.p2.y);
 
-        _cairo_gstate_backend_to_user_rectangle (gstate, x1, y1, x2, y2, NULL);
+        _cairo_gstate_backend_to_user_rectangle (gstate,
+						 &px1, &py1, &px2, &py2,
+						 NULL);
+	if (x1)
+	    *x1 = px1;
+	if (y1)
+	    *y1 = py1;
+	if (x2)
+	    *x2 = px2;
+	if (y2)
+	    *y2 = py2;
     }
 }
 
@@ -1128,7 +1149,8 @@ _cairo_gstate_stroke_extents (cairo_gstate_t	 *gstate,
 						gstate->tolerance,
 						&traps);
     if (status == CAIRO_STATUS_SUCCESS) {
-        _cairo_gstate_traps_extents_to_user_rectangle(gstate, &traps, x1, y1, x2, y2);
+	_cairo_gstate_traps_extents_to_user_rectangle (gstate, &traps,
+						       x1, y1, x2, y2);
     }
 
     _cairo_traps_fini (&traps);
@@ -1152,7 +1174,8 @@ _cairo_gstate_fill_extents (cairo_gstate_t     *gstate,
 					      gstate->tolerance,
 					      &traps);
     if (status == CAIRO_STATUS_SUCCESS) {
-        _cairo_gstate_traps_extents_to_user_rectangle(gstate, &traps, x1, y1, x2, y2);
+	_cairo_gstate_traps_extents_to_user_rectangle (gstate, &traps,
+						       x1, y1, x2, y2);
     }
 
     _cairo_traps_fini (&traps);
@@ -1195,26 +1218,34 @@ cairo_status_t
 _cairo_gstate_clip_extents (cairo_gstate_t *gstate,
 		            double         *x1,
 		            double         *y1,
-        		    double         *x2,
-        		    double         *y2)
+			    double         *x2,
+			    double         *y2)
 {
     cairo_rectangle_int_t extents;
+    double px1, py1, px2, py2;
     cairo_status_t status;
-    
+
     status = _cairo_gstate_int_clip_extents (gstate, &extents);
     if (status)
         return status;
 
-    if (x1)
-	*x1 = extents.x;
-    if (y1)
-	*y1 = extents.y;
-    if (x2)
-	*x2 = extents.x + extents.width;
-    if (y2)
-	*y2 = extents.y + extents.height;
+    px1 = extents.x;
+    py1 = extents.y;
+    px2 = extents.x + (int) extents.width;
+    py2 = extents.y + (int) extents.height;
 
-    _cairo_gstate_backend_to_user_rectangle (gstate, x1, y1, x2, y2, NULL);
+    _cairo_gstate_backend_to_user_rectangle (gstate,
+					     &px1, &py1, &px2, &py2,
+					     NULL);
+
+    if (x1)
+	*x1 = px1;
+    if (y1)
+	*y1 = py1;
+    if (x2)
+	*x2 = px2;
+    if (y2)
+	*y2 = py2;
 
     return CAIRO_STATUS_SUCCESS;
 }