[librsvg: 1/5] (#335): Don't panic if the toplevel node is not <svg>

[Federico Mena Quintero <federico src gnome org>]

commit a8307ac419ded7e074c10155b476add353890941
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Sep 13 08:01:27 2018 -0500

    (#335): Don't panic if the toplevel node is not <svg>
    
    In standard_element_start(), we were only setting the tree root if the
    first element in the file was an <svg> element.  Otherwise we would
    simply unref the element at the end of the function.  This caused its
    first child to be left with weak reference to a dead parent; the
    subsequent call to child.get_parent() would upgrade().unwrap() on the
    weak reference, and the unwrap() would panic as the parent is already
    dead.
    
    https://gitlab.gnome.org/GNOME/librsvg/issues/335

 librsvg/rsvg-load.c                           |  7 +++----
 rsvg_internals/src/load.rs                    | 17 -----------------
 tests/fixtures/crash/335-non-svg-toplevel.svg |  1 +
 3 files changed, 4 insertions(+), 21 deletions(-)
---
diff --git a/librsvg/rsvg-load.c b/librsvg/rsvg-load.c
index 40996eae..f3f3bdbe 100644
--- a/librsvg/rsvg-load.c
+++ b/librsvg/rsvg-load.c
@@ -40,7 +40,7 @@ typedef enum {
 
 /* Implemented in rsvg_internals/src/load.rs */
 G_GNUC_INTERNAL
-RsvgNode *rsvg_load_new_node (const char *element_name, RsvgNode *parent, RsvgPropertyBag *atts, RsvgDefs 
*defs, gboolean *is_svg);
+RsvgNode *rsvg_load_new_node (const char *element_name, RsvgNode *parent, RsvgPropertyBag *atts, RsvgDefs 
*defs);
 
 /* Implemented in rsvg_internals/src/load.rs */
 G_GNUC_INTERNAL
@@ -298,18 +298,17 @@ standard_element_start (RsvgLoad *load, const char *name, RsvgPropertyBag * atts
 {
     RsvgDefs *defs;
     RsvgNode *newnode;
-    gboolean is_svg;
 
     defs = rsvg_handle_get_defs(load->handle);
 
-    newnode = rsvg_load_new_node(name, load->currentnode, atts, defs, &is_svg);
+    newnode = rsvg_load_new_node(name, load->currentnode, atts, defs);
 
     push_element_name (load, name);
 
     if (load->currentnode) {
         rsvg_node_add_child (load->currentnode, newnode);
         load->currentnode = rsvg_node_unref (load->currentnode);
-    } else if (is_svg) {
+    } else {
         load->tree = rsvg_tree_new (newnode);
     }
 
diff --git a/rsvg_internals/src/load.rs b/rsvg_internals/src/load.rs
index b3807701..235d23cd 100644
--- a/rsvg_internals/src/load.rs
+++ b/rsvg_internals/src/load.rs
@@ -1,5 +1,3 @@
-use glib::translate::*;
-use glib_sys;
 use libc;
 use std::collections::HashMap;
 
@@ -271,7 +269,6 @@ pub extern "C" fn rsvg_load_new_node(
     parent: *const RsvgNode,
     pbag: *const PropertyBag<'_>,
     defs: *mut RsvgDefs,
-    out_is_svg: *mut glib_sys::gboolean,
 ) -> *const RsvgNode {
     assert!(!raw_name.is_null());
     assert!(!pbag.is_null());
@@ -307,25 +304,11 @@ pub extern "C" fn rsvg_load_new_node(
     let node = create_fn(id, class, parent);
     assert!(!node.is_null());
 
-    let is_svg = {
-        let n: &RsvgNode = unsafe { &*node };
-        match n.get_type() {
-            NodeType::Invalid => unreachable!(),
-            NodeType::Svg => true,
-            _ => false,
-        }
-    };
-
     if id.is_some() {
         let n = unsafe { &*node };
         defs.insert(id.unwrap(), n);
     }
 
-    assert!(!out_is_svg.is_null());
-    unsafe {
-        *out_is_svg = is_svg.to_glib();
-    }
-
     node
 }
 
diff --git a/tests/fixtures/crash/335-non-svg-toplevel.svg b/tests/fixtures/crash/335-non-svg-toplevel.svg
new file mode 100644
index 00000000..f9aefcbe
--- /dev/null
+++ b/tests/fixtures/crash/335-non-svg-toplevel.svg
@@ -0,0 +1 @@
+<x><x></x>