Fixes for bug #4110:

Don't call _cairo_ft_unscaled_font_init_key in the from_face case, just clear filename and id instead. Initialize unscaled->base first so that initialization order matches the structure declaration order.
Fix to accept a NULL string and hash it identically to a zero-length string.
Add a test that calls cairo_ft_font_create_for_ft_face to demonstrate bug #4110.

ChangeLog

@@ -1,3 +1,19 @@
+2005-08-17  Carl Worth  <cworth@cworth.org>
+
+ 	Fixes for bug #4110:
+
+	* src/cairo-ft-font.c (_cairo_ft_unscaled_font_init): Don't call
+	_cairo_ft_unscaled_font_init_key in the from_face case, just clear
+	filename and id instead. Initialize unscaled->base first so that
+	initialization order matches the structure declaration order.
+
+	* src/cairo-cache.c (_cairo_hash_string): Fix to accept a NULL
+	string and hash it identically to a zero-length string.
+
+	* test/Makefile.am:
+	* test/ft-font-create-for-ft-face: Add a test that calls
+	cairo_ft_font_create_for_ft_face to demonstrate bug #4110.
+
 2005-08-16  Billy Biggs  <vektor@dumbterm.net>
 
 	* test/filter-nearest-offset.c: (draw): Fix the filter-nearest-offset
@@ -51,7 +67,7 @@
 
 	* configure.in: Add a check for the MMX intrinsics used by pixman.
 	gcc >= 3.4 is required.
-
+ 
 2005-08-16  Carl Worth  <cworth@cworth.org>
 
 	* src/cairoint.h (CAIRO_PRINTF_FORMAT): Rename cairo_printf_format

src/cairo-cache.c

@@ -512,7 +512,7 @@ _cairo_hash_string (const char *c)
 {
     /* This is the djb2 hash. */
     unsigned long hash = 5381;
-    while (*c)
+    while (c && *c)
 	hash = ((hash << 5) + hash) + *c++;
     return hash;
 }

src/cairo-ft-font.c

@@ -290,22 +290,25 @@ _cairo_ft_unscaled_font_init (cairo_ft_unscaled_font_t *unscaled,
 			      int			id,
 			      FT_Face			face)
 {
-    char *filename_copy = NULL;
+    _cairo_unscaled_font_init (&unscaled->base,
+			       &cairo_ft_unscaled_font_backend);
+
+    if (face) {
+	unscaled->from_face = TRUE;
+	unscaled->face = face;
+	unscaled->filename = NULL;
+	unscaled->id = 0;
+    } else {
+	char *filename_copy;
+
+	unscaled->from_face = FALSE;
+	unscaled->face = NULL;
 
-    if (filename) {
 	filename_copy = strdup (filename);
 	if (filename_copy == NULL)
 	    return CAIRO_STATUS_NO_MEMORY;
-    }
 
-    _cairo_ft_unscaled_font_init_key (unscaled, filename_copy, id);
-
-    if (face) {
-	unscaled->from_face = 1;
-	unscaled->face = face;
-    } else {
-	unscaled->from_face = 0;
-	unscaled->face = NULL;
+	_cairo_ft_unscaled_font_init_key (unscaled, filename_copy, id);
     }
 
     unscaled->have_scale = 0;
@@ -313,9 +316,6 @@ _cairo_ft_unscaled_font_init (cairo_ft_unscaled_font_t *unscaled,
     
     unscaled->faces = NULL;
 
-    _cairo_unscaled_font_init (&unscaled->base,
-			       &cairo_ft_unscaled_font_backend);
-
     return CAIRO_STATUS_SUCCESS;
 }
 

test/.cvsignore

@@ -15,6 +15,7 @@ create-from-png-stream
 fill-and-stroke
 fill-rule
 filter-nearest-offset
+ft-font-create-for-ft-face
 get-and-set
 gradient-alpha
 imagediff

test/Makefile.am

@@ -47,6 +47,10 @@ unbounded-operator		\
 user-data			\
 rel-path
 
+if CAIRO_HAS_FT_FONT
+TESTS += ft-font-create-for-ft-face
+endif
+
 if CAIRO_HAS_PDF_SURFACE
 TESTS += pdf-surface pdf-clip
 endif
@@ -174,6 +178,7 @@ create_from_png_stream_LDADD = $(LDADDS)
 fill_and_stroke_LDADD = $(LDADDS)
 fill_rule_LDADD = $(LDADDS)
 filter_nearest_offset_LDADD = $(LDADDS)
+ft_font_create_for_ft_face_LDADD = $(LDADDS)
 get_and_set_LDADD = $(LDADDS)
 gradient_alpha_LDADD = $(LDADDS)
 leaky_polygon_LDADD = $(LDADDS)

test/ft-font-create-for-ft-face.c

@@ -0,0 +1,102 @@
+/*
+ * Copyright © 2005 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 <cairo-ft.h>
+
+cairo_test_t test = {
+    "ft-font-create-for-ft-face",
+    "Simple test to verify that cairo_ft_font_create_for_ft_face doesn't crash.",
+    0, 0
+};
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    FcPattern *pattern;
+    cairo_font_face_t *font_face;
+    cairo_scaled_font_t *scaled_font;
+    cairo_font_options_t *font_options;
+    cairo_font_extents_t font_extents;
+    cairo_matrix_t font_matrix, ctm;
+    FT_Face ft_face;
+
+    /* We're trying here to get our hands on _some_ FT_Face but we do
+     * not at all care which one, so an empty pattern should work just
+     * fine. */
+    pattern = FcPatternCreate ();
+    if (!pattern)
+	return CAIRO_TEST_FAILURE;
+
+    font_face = cairo_ft_font_face_create_for_pattern (pattern);
+
+    cairo_matrix_init_identity (&font_matrix);
+
+    cairo_get_matrix (cr, &ctm);
+
+    font_options = cairo_font_options_create ();
+
+    scaled_font = cairo_scaled_font_create (font_face,
+					    &font_matrix,
+					    &ctm,
+					    font_options);
+
+    ft_face = cairo_ft_scaled_font_lock_face (scaled_font);
+
+    cairo_font_options_destroy (font_options);
+    cairo_font_face_destroy (font_face);
+    FcPatternDestroy (pattern);
+
+    if (!ft_face) {
+	cairo_scaled_font_destroy (scaled_font);
+	return CAIRO_TEST_FAILURE;
+    }
+
+    /* phew, that was a lot of work. But at least we didn't ever have
+     * to call freetype directly, nor did we have to make many (any?)
+     * assumptions about the current system.
+     *
+     * Now, on to the simple thing we actually want to test.
+     */
+    font_face = cairo_ft_font_face_create_for_ft_face (ft_face, 0);
+
+    /* Set the font_face and force cairo to actually use it for
+     * something. */
+    cairo_set_font_face (cr, font_face);
+    cairo_font_extents (cr, &font_extents);
+
+    /* Finally, even more cleanup */
+    cairo_font_face_destroy (font_face);
+    cairo_ft_scaled_font_unlock_face (scaled_font);
+    cairo_scaled_font_destroy (scaled_font);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+int
+main (void)
+{
+    return cairo_test (&test, draw);
+}