Be explicit about how stop-color and stop-opacity are inherited

These can live in the <stop> element attributes, or in its style="..."
attribute.

Neither of them inherits by default; they have to be explicitly
specified as "inherit" to do that.

Inheritance is from the gradient's parent element, not from where it is
referenced, hence the call to rsvg_state_reconstruct().

Also, stop-color can be currentColor.

We now have explicit enums to indicate all of these cases.  Previously,
all the meanings were overloaded into state->has_stop_color and
state->has_stop_opacity, and those didn't handle all cases correctly.

Added the hexchat.svg icon to the tests, which is how I caught the lack
of proper handling for style="stop-color: ...;".

1 files changed, 15 insertions, 0 deletions

diff --git a/rsvg-styles.h b/rsvg-styles.h
index b4d59624..8205d999 100644
--- a/rsvg-styles.h
+++ b/rsvg-styles.h
@@ -72,6 +72,19 @@ struct _RsvgVpathDash {
     double *dash;
 };
 
+typedef enum {
+    STOP_COLOR_UNSPECIFIED,
+    STOP_COLOR_SPECIFIED,
+    STOP_COLOR_INHERIT,
+    STOP_COLOR_CURRENT_COLOR
+} StopColor;
+
+typedef enum {
+    STOP_OPACITY_UNSPECIFIED,
+    STOP_OPACITY_SPECIFIED,
+    STOP_OPACITY_INHERIT
+} StopOpacity;
+
 /* end libart theft... */
 
 struct _RsvgState {
@@ -143,8 +156,10 @@ struct _RsvgState {
 
     guint32 stop_color;         /* rgb */
     gboolean has_stop_color;
+    StopColor stop_color_mode;
     gint stop_opacity;          /* 0..255 */
     gboolean has_stop_opacity;
+    StopOpacity stop_opacity_mode;
 
     gboolean visible;
     gboolean has_visible;