From 57851464f920d52444d19d25e78293fa0f40c5f9 Mon Sep 17 00:00:00 2001
From: Benjamin Otte <otte@gnome.org>
Date: Sun, 28 Sep 2008 17:02:23 +0200
Subject: [PATCH] [SVG] make backend handle new operators gracefully

Previously, the SVG backend would rash when new operators were added to
cairo.h, now it returns UNSUPPORTED.
Also unsupported operators can now be set as NULL, so image fallbacks can
be used properly.
Should use fallbacks instead of color-dodge for CAIRO_OPERATOR_STURATE?
---
 src/cairo-svg-surface.c | 45 ++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 14 deletions(-)

diff --git a/src/cairo-svg-surface.c b/src/cairo-svg-surface.c
index bedce5d0d..13a1261ea 100644
--- a/src/cairo-svg-surface.c
+++ b/src/cairo-svg-surface.c
@@ -766,6 +766,36 @@ _cairo_svg_document_emit_font_subsets (cairo_svg_document_t *document)
     return status;
 }
 
+char const *_cairo_svg_surface_operators[] = {
+    "clear",
+
+    "src", "src-over", "src-in",
+    "src-out", "src-atop",
+
+    "dst", "dst-over", "dst-in",
+    "dst-out", "dst-atop",
+
+    "xor", "plus",
+    "color-dodge", /* FIXME: saturate ? */
+};
+
+static cairo_bool_t cairo_svg_force_fallbacks = FALSE;
+
+static cairo_bool_t
+_cairo_svg_surface_analyze_operator (cairo_svg_surface_t   *surface,
+				      cairo_operator_t	     op)
+{
+    /* guard against newly added operators */
+    if (op >= ARRAY_LENGTH (_cairo_svg_surface_operators))
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    /* allow operators being NULL if they are unsupported */
+    if (_cairo_svg_surface_operators[op] == NULL)
+	return CAIRO_INT_STATUS_UNSUPPORTED;
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
 static cairo_int_status_t
 _cairo_svg_surface_analyze_operation (cairo_svg_surface_t   *surface,
 				      cairo_operator_t	     op,
@@ -782,7 +812,7 @@ _cairo_svg_surface_analyze_operation (cairo_svg_surface_t   *surface,
 	return CAIRO_INT_STATUS_UNSUPPORTED;
 
     if (document->svg_version >= CAIRO_SVG_VERSION_1_2)
-	return CAIRO_STATUS_SUCCESS;
+	return _cairo_svg_surface_analyze_operator (surface, op);
 
     if (op == CAIRO_OPERATOR_OVER)
 	return CAIRO_STATUS_SUCCESS;
@@ -965,19 +995,6 @@ _cairo_surface_base64_encode (cairo_surface_t       *surface,
     return status;
 }
 
-char const *_cairo_svg_surface_operators[] = {
-    "clear",
-
-    "src", "src-over", "src-in",
-    "src-out", "src-atop",
-
-    "dst", "dst-over", "dst-in",
-    "dst-out", "dst-atop",
-
-    "xor", "plus",
-    "color-dodge", /* FIXME: saturate ? */
-};
-
 static void
 _cairo_svg_surface_emit_operator (cairo_output_stream_t *output,
 				  cairo_svg_surface_t   *surface,