Merge branch 'rectangle-box-negative-extents' into 'master'

[matrix] Handle bounding-box extents overflow during transformation

See merge request cairo/cairo!645

src/cairo-rectangle.c

@@ -53,10 +53,10 @@ _cairo_box_from_doubles (cairo_box_t *box,
 			 double *x1, double *y1,
 			 double *x2, double *y2)
 {
-    box->p1.x = _cairo_fixed_from_double (*x1);
-    box->p1.y = _cairo_fixed_from_double (*y1);
-    box->p2.x = _cairo_fixed_from_double (*x2);
-    box->p2.y = _cairo_fixed_from_double (*y2);
+    box->p1.x = _cairo_fixed_from_double_clamped (*x1, 0);
+    box->p1.y = _cairo_fixed_from_double_clamped (*y1, 0);
+    box->p2.x = _cairo_fixed_from_double_clamped (*x2, 0);
+    box->p2.y = _cairo_fixed_from_double_clamped (*y2, 0);
 }
 
 cairo_private void

test/meson.build

@@ -294,6 +294,7 @@ test_sources = [
   'record-transform-paint.c',
   'record-write-png.c',
   'recording-ink-extents.c',
+  'recording-ink-extents-overflow.c',
   'recording-surface-pattern.c',
   'recording-surface-extend.c',
   'rectangle-rounding-error.c',

test/recording-ink-extents-overflow.c

@@ -0,0 +1,101 @@
+/*
+ * Copyright © 2026
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "cairo-test.h"
+
+/* Verify that transforming recording-pattern bounds during analysis does not
+ * produce wrapped fixed-point boxes with empty extents.
+ */
+
+static cairo_test_status_t
+preamble (cairo_test_context_t *ctx)
+{
+    cairo_rectangle_t extents = { 0, 0, 1, 1 };
+    cairo_surface_t *source_surface;
+    cairo_surface_t *recording_surface;
+    cairo_pattern_t *pattern;
+    cairo_t *cr;
+    cairo_matrix_t matrix;
+    cairo_status_t status;
+    double x, y, width, height;
+
+    source_surface = cairo_recording_surface_create (CAIRO_CONTENT_COLOR_ALPHA, &extents);
+    cr = cairo_create (source_surface);
+    cairo_rectangle (cr, 0, 0, 1, 1);
+    cairo_fill (cr);
+    status = cairo_status (cr);
+    cairo_destroy (cr);
+    if (status) {
+	cairo_surface_destroy (source_surface);
+	return cairo_test_status_from_status (ctx, status);
+    }
+
+    recording_surface = cairo_recording_surface_create (CAIRO_CONTENT_COLOR_ALPHA, NULL);
+    cr = cairo_create (recording_surface);
+    pattern = cairo_pattern_create_for_surface (source_surface);
+    cairo_surface_destroy (source_surface);
+
+    /* This invertible matrix causes transformed bbox coordinates to exceed
+     * the fixed-point range and exercises clamping in
+     * _cairo_matrix_transform_bounding_box_fixed().
+     */
+    cairo_matrix_init (&matrix, -70000.0, 50000.0, -100000.0,
+		       100000.0, -100000000.0, -50000000.0);
+    cairo_pattern_set_matrix (pattern, &matrix);
+    status = cairo_pattern_status (pattern);
+    if (!status) {
+	cairo_set_source (cr, pattern);
+	cairo_paint (cr);
+	status = cairo_status (cr);
+    }
+
+    cairo_pattern_destroy (pattern);
+    cairo_destroy (cr);
+    if (status) {
+	cairo_surface_destroy (recording_surface);
+	return cairo_test_status_from_status (ctx, status);
+    }
+
+    cairo_recording_surface_ink_extents (recording_surface, &x, &y, &width, &height);
+    status = cairo_surface_status (recording_surface);
+    cairo_surface_destroy (recording_surface);
+    if (status)
+	return cairo_test_status_from_status (ctx, status);
+
+    if (width <= 0 || height <= 0) {
+	cairo_test_log (ctx,
+			"ink extents should be non-empty, got (%g, %g, %g, %g)\n",
+			x, y, width, height);
+	return CAIRO_TEST_FAILURE;
+    }
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (recording_ink_extents_overflow,
+	    "Test cairo_recording_surface_ink_extents() with overflow-prone recording pattern matrix",
+	    "recording,extents,transform", /* keywords */
+	    NULL, /* requirements */
+	    0, 0,
+	    preamble, NULL)