test/show-glyphs-many: New test case to demonstrate bug #5528

This demonstrates an Xlib crash when rendering many glyphs. See:

	_XError from XRenderCompositeText8
	https://bugs.freedesktop.org/show_bug.cgi?id=5528

for more details.

1 files changed, 127 insertions, 0 deletions

diff --git a/test/show-glyphs-many.c b/test/show-glyphs-many.c
new file mode 100644
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--- /dev/null
+++ b/test/show-glyphs-many.c
@@ -0,0 +1,127 @@
+/*
+ * Copyright © 2006 Red Hat, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Red Hat, Inc. not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Red Hat, Inc. makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL RED HAT, INC. BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Carl D. Worth <cworth@cworth.org>
+ */
+
+#include "cairo-test.h"
+
+#include <string.h>
+
+/* Bug history
+ *
+ * 2006-01-07  Jon Hellan  <hellan@acm.org>
+ *
+ *   Jon opened the following bug report:
+ *
+ *	_XError from XRenderCompositeText8
+ *	https://bugs.freedesktop.org/show_bug.cgi?id=5528
+ *
+ * 2006-03-02  Carl Worth  <cworth@cworth.org>
+ *
+ *   I wrote this test case to demonstrate the bug.
+ *
+ *   Approach:
+ *
+ *	Draw 65535 glyphs white-on-white all on top of each other.
+ *
+ *   Rationale:
+ *
+ *	The number 65535 comes from the original bug report.
+ *
+ *	I would use cairo_show_text with a long string of 'x's say,
+ *	but then the surface would need to be enormous to contain
+ *	them. A smaller surface could be used, but I fear that at some
+ *	point the off-surface glyph drawing would be optimized away
+ *	and not exercise the bug.
+ *
+ *	So, to keep the surface size under control, I use
+ *	cairo_show_glyphs which allows me to place the glyphs all on
+ *	top of each other. But, since cairo doesn't provide any
+ *	character-to-glyphs mapping, I can't get a reliable glyph
+ *	index (for character 'x' for example). So I just "guess" a
+ *	glyph index and use white-on-white drawing to ignore the
+ *	result. (I don't care what's drawn---I just want to ensure
+ *	that things don't crash.)
+ *
+ *  Status: I replicated bug. The largest value of NUM_GLYPHS for
+ *      which I saw success is 21842.
+ */
+
+#define TEXT_SIZE 12
+#define NUM_GLYPHS 65535
+
+/* This is the index into the font for what glyph we'll draw. Since we
+ * don't guarantee we'll get any particular font, we can't relibably
+ * get any particular glyph. But we don't care what we draw anyway,
+ * (see discussion of white-on-white drawing above). For what it's
+ * worth, this appears to be giving me 'M' with Bitstream Vera
+ * Sans Mono. */
+#define GLYPH_INDEX 48
+
+cairo_test_t test = {
+    "show-glyphs-many",
+    "Test that cairo_show_glyps works when handed 'many' glyphs",
+    9, 11
+};
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_glyph_t glyphs[NUM_GLYPHS];
+    cairo_font_options_t *font_options;
+    int i;
+
+    /* Initialize our giant array of glyphs. */
+    for (i=0; i < NUM_GLYPHS; i++) {
+	glyphs[i].index = GLYPH_INDEX;
+	glyphs[i].x = 1.0;
+	glyphs[i].y = height - 1;
+    }
+
+    /* Paint white background. */
+    cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
+    cairo_paint (cr);
+
+    cairo_select_font_face (cr, "Bitstream Vera Sans Mono",
+			    CAIRO_FONT_SLANT_NORMAL,
+			    CAIRO_FONT_WEIGHT_NORMAL);
+    cairo_set_font_size (cr, TEXT_SIZE);
+
+    font_options = cairo_font_options_create ();
+
+    cairo_font_options_set_hint_style (font_options, CAIRO_HINT_STYLE_NONE);
+    cairo_font_options_set_antialias (font_options, CAIRO_ANTIALIAS_GRAY);
+
+    cairo_set_font_options (cr, font_options);
+    cairo_font_options_destroy (font_options);
+
+    cairo_show_glyphs (cr, glyphs, NUM_GLYPHS);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+int
+main (void)
+{
+    return cairo_test (&test, draw);
+}