[librsvg: 1/2] Expand `font:inherit` and `marker:inherit`

[Marge Bot <marge-bot src gnome org>]

commit b6cb910167cd042f3c7b15012cc35e3337791623
Author: Michael Howell <michael notriddle com>
Date:   Sun Oct 10 15:37:46 2021 -0700

    Expand `font:inherit` and `marker:inherit`
    
    Fixes #800
    
    Part-of: <https://gitlab.gnome.org/GNOME/librsvg/-/merge_requests/602>

 src/properties.rs                         | 40 +++++++++++++++++++++++++++++++
 tests/fixtures/crash/800-font-inherit.svg |  1 +
 tests/fixtures/crash/800-marker.svg       |  1 +
 3 files changed, 42 insertions(+)
---
diff --git a/src/properties.rs b/src/properties.rs
index cefcdce6..d2ea9f85 100644
--- a/src/properties.rs
+++ b/src/properties.rs
@@ -542,6 +542,12 @@ impl SpecifiedValues {
             ParsedProperty::Marker(SpecifiedValue::Specified(ref m)) => {
                 self.expand_marker_shorthand(m, replace)
             }
+            ParsedProperty::Font(SpecifiedValue::Inherit) => {
+                self.expand_font_shorthand_inherit(replace)
+            }
+            ParsedProperty::Marker(SpecifiedValue::Inherit) => {
+                self.expand_marker_shorthand_inherit(replace)
+            }
 
             _ => self.set_property(prop, replace),
         }
@@ -605,6 +611,40 @@ impl SpecifiedValues {
         );
     }
 
+    fn expand_font_shorthand_inherit(&mut self, replace: bool) {
+        self.set_property(&ParsedProperty::FontStyle(SpecifiedValue::Inherit), replace);
+        self.set_property(
+            &ParsedProperty::FontVariant(SpecifiedValue::Inherit),
+            replace,
+        );
+        self.set_property(
+            &ParsedProperty::FontWeight(SpecifiedValue::Inherit),
+            replace,
+        );
+        self.set_property(
+            &ParsedProperty::FontStretch(SpecifiedValue::Inherit),
+            replace,
+        );
+        self.set_property(&ParsedProperty::FontSize(SpecifiedValue::Inherit), replace);
+        self.set_property(
+            &ParsedProperty::LineHeight(SpecifiedValue::Inherit),
+            replace,
+        );
+        self.set_property(
+            &ParsedProperty::FontFamily(SpecifiedValue::Inherit),
+            replace,
+        );
+    }
+
+    fn expand_marker_shorthand_inherit(&mut self, replace: bool) {
+        self.set_property(
+            &ParsedProperty::MarkerStart(SpecifiedValue::Inherit),
+            replace,
+        );
+        self.set_property(&ParsedProperty::MarkerMid(SpecifiedValue::Inherit), replace);
+        self.set_property(&ParsedProperty::MarkerEnd(SpecifiedValue::Inherit), replace);
+    }
+
     pub fn set_parsed_property(&mut self, prop: &ParsedProperty) {
         self.set_property_expanding_shorthands(prop, true);
     }
diff --git a/tests/fixtures/crash/800-font-inherit.svg b/tests/fixtures/crash/800-font-inherit.svg
new file mode 100644
index 00000000..517af776
--- /dev/null
+++ b/tests/fixtures/crash/800-font-inherit.svg
@@ -0,0 +1 @@
+<svg><text style="font: inherit"></text><text styyle=""></text></svg>
diff --git a/tests/fixtures/crash/800-marker.svg b/tests/fixtures/crash/800-marker.svg
new file mode 100644
index 00000000..ac7020fd
--- /dev/null
+++ b/tests/fixtures/crash/800-marker.svg
@@ -0,0 +1 @@
+<svg width="10" height="10"><text style="marker: inherit"></text></svg>