[librsvg/rustification] Use an accessor function rsvg_node_get_parent() throughout

[Federico Mena Quintero <federico src gnome org>]

commit d1ef96e0e4c5075a5ef34df5703c6adcb49c35b0
Author: Federico Mena Quintero <federico gnome org>
Date:   Tue Nov 22 14:43:56 2016 -0600

    Use an accessor function rsvg_node_get_parent() throughout
    
    Also, fix a three-part hack:
    
    1. rsvg_standard_element_start() would set the new node's parent right
       there, in redundant fashion to where rsvg_node_group_pack() sets the
       node's parent.
    
    2. Make rsvg_standard_element_start() add the new node to its parent
       before node->set_atts() gets called...
    
    3. ... so that rsvg_stop_set_atts() doesn't have to set its own parent
       to ctx->priv->currentnode (!) because the stop's node hasn't been
       parented yet.  This was the only place where a node->parent gets
       overwritten after creation.

 rsvg-base.c         |   20 +++++++++++++-------
 rsvg-cairo-render.c |    4 ++--
 rsvg-paint-server.c |    2 --
 rsvg-private.h      |    3 +++
 rsvg-structure.c    |   17 ++++++++++-------
 rsvg-styles.c       |    2 +-
 6 files changed, 29 insertions(+), 19 deletions(-)
---
diff --git a/rsvg-base.c b/rsvg-base.c
index f259c58..9b6f651 100644
--- a/rsvg-base.c
+++ b/rsvg-base.c
@@ -415,21 +415,21 @@ rsvg_standard_element_start (RsvgHandle * ctx, const char *name, RsvgPropertyBag
 
     if (newnode) {
         g_assert (RSVG_NODE_TYPE (newnode) != RSVG_NODE_TYPE_INVALID);
-        newnode->parent = ctx->priv->currentnode;
 
         push_element_name (ctx, name);
 
         add_node_to_handle (ctx, newnode);
         register_node_in_defs (ctx, newnode, atts);
-        node_set_atts (newnode, ctx, creator, atts);
 
         if (ctx->priv->currentnode) {
             rsvg_node_group_pack (ctx->priv->currentnode, newnode);
-            ctx->priv->currentnode = newnode;
         } else if (RSVG_NODE_TYPE (newnode) == RSVG_NODE_TYPE_SVG) {
             ctx->priv->treebase = newnode;
-            ctx->priv->currentnode = newnode;
         }
+
+        ctx->priv->currentnode = newnode;
+
+        node_set_atts (newnode, ctx, creator, atts);
     }
 }
 
@@ -439,6 +439,12 @@ rsvg_node_get_state (RsvgNode *node)
     return node->state;
 }
 
+RsvgNode *
+rsvg_node_get_parent (RsvgNode *node)
+{
+    return node->parent;
+}
+
 /* extra (title, desc, metadata) */
 
 static void
@@ -837,7 +843,7 @@ rsvg_end_element (void *data, const xmlChar * xmlname)
         }
 
         if (ctx->priv->currentnode && topmost_element_name_is (ctx, name)) {
-            ctx->priv->currentnode = ctx->priv->currentnode->parent;
+            ctx->priv->currentnode = rsvg_node_get_parent (ctx->priv->currentnode);
             pop_element_name (ctx);
         }
 
@@ -1539,7 +1545,7 @@ rsvg_handle_get_dimensions_sub (RsvgHandle * handle, RsvgDimensionData * dimensi
 
         while (sself != NULL) {
             draw->drawsub_stack = g_slist_prepend (draw->drawsub_stack, sself);
-            sself = sself->parent;
+            sself = rsvg_node_get_parent (sself);
         }
 
         rsvg_state_push (draw);
@@ -1636,7 +1642,7 @@ rsvg_handle_get_position_sub (RsvgHandle * handle, RsvgPositionData * position_d
 
     while (node != NULL) {
         draw->drawsub_stack = g_slist_prepend (draw->drawsub_stack, node);
-        node = node->parent;
+        node = rsvg_node_get_parent (node);
     }
 
     rsvg_state_push (draw);
diff --git a/rsvg-cairo-render.c b/rsvg-cairo-render.c
index f75d331..f196e70 100644
--- a/rsvg-cairo-render.c
+++ b/rsvg-cairo-render.c
@@ -217,13 +217,13 @@ rsvg_handle_render_cairo_sub (RsvgHandle * handle, cairo_t * cr, const char *id)
 
     while (drawsub != NULL) {
         draw->drawsub_stack = g_slist_prepend (draw->drawsub_stack, drawsub);
-        drawsub = drawsub->parent;
+        drawsub = rsvg_node_get_parent (drawsub);
     }
 
     rsvg_state_push (draw);
     cairo_save (cr);
 
-    rsvg_node_draw ((RsvgNode *) handle->priv->treebase, draw, 0);
+    rsvg_node_draw (handle->priv->treebase, draw, 0);
 
     cairo_restore (cr);
     rsvg_state_pop (draw);
diff --git a/rsvg-paint-server.c b/rsvg-paint-server.c
index 0871ec9..e5477c9 100644
--- a/rsvg-paint-server.c
+++ b/rsvg-paint-server.c
@@ -197,8 +197,6 @@ rsvg_stop_set_atts (RsvgNode * self, RsvgHandle * ctx, RsvgPropertyBag * atts)
 
     rsvg_parse_style_pairs (ctx, rsvg_node_get_state (self), atts);
 
-    self->parent = ctx->priv->currentnode;
-
     state = rsvg_state_new ();
     rsvg_state_reconstruct (state, self);
 
diff --git a/rsvg-private.h b/rsvg-private.h
index b51c9e3..a5d55a8 100644
--- a/rsvg-private.h
+++ b/rsvg-private.h
@@ -343,6 +343,9 @@ struct _RsvgNode {
 G_GNUC_INTERNAL
 RsvgState *rsvg_node_get_state (RsvgNode *node);
 
+G_GNUC_INTERNAL
+RsvgNode *rsvg_node_get_parent (RsvgNode *node);
+
 struct _RsvgNodeChars {
     RsvgNode super;
     GString *contents;
diff --git a/rsvg-structure.c b/rsvg-structure.c
index 43e396c..ab6ec6d 100644
--- a/rsvg-structure.c
+++ b/rsvg-structure.c
@@ -142,10 +142,10 @@ rsvg_node_is_ancestor (RsvgNode * potential_ancestor, RsvgNode * potential_desce
     while (TRUE) {
         if (potential_ancestor == potential_descendant)
             return TRUE;
-        else if (potential_descendant->parent == NULL)
+        else if (rsvg_node_get_parent (potential_descendant) == NULL)
             return FALSE;
         else
-            potential_descendant = potential_descendant->parent;
+            potential_descendant = rsvg_node_get_parent (potential_descendant);
     }
 
     g_assert_not_reached ();
@@ -274,7 +274,7 @@ rsvg_node_svg_draw (RsvgNode * self, RsvgDrawingCtx * ctx, int dominate)
 
     /* Bounding box addition must be AFTER the discrete layer push, 
        which must be AFTER the transformation happens. */
-    if (!state->overflow && self->parent) {
+    if (!state->overflow && rsvg_node_get_parent (self)) {
         state->affine = affine_old;
         rsvg_add_clipping_rect (ctx, nx, ny, nw, nh);
         state->affine = affine_new;
@@ -309,10 +309,13 @@ rsvg_node_svg_set_atts (RsvgNode * self, RsvgHandle * ctx, RsvgPropertyBag * att
      * x & y attributes have no effect on outermost svg
      * http://www.w3.org/TR/SVG/struct.html#SVGElement 
      */
-    if (self->parent && (value = rsvg_property_bag_lookup (atts, "x")))
-        svg->x = rsvg_length_parse (value, LENGTH_DIR_HORIZONTAL);
-    if (self->parent && (value = rsvg_property_bag_lookup (atts, "y")))
-        svg->y = rsvg_length_parse (value, LENGTH_DIR_VERTICAL);
+    if (rsvg_node_get_parent (self)) {
+        if ((value = rsvg_property_bag_lookup (atts, "x")))
+            svg->x = rsvg_length_parse (value, LENGTH_DIR_HORIZONTAL);
+
+        if ((value = rsvg_property_bag_lookup (atts, "y")))
+            svg->y = rsvg_length_parse (value, LENGTH_DIR_VERTICAL);
+    }
 
     /*
      * style element is not loaded yet here, so we need to store those attribues
diff --git a/rsvg-styles.c b/rsvg-styles.c
index 4401936..8ad677c 100644
--- a/rsvg-styles.c
+++ b/rsvg-styles.c
@@ -1725,6 +1725,6 @@ rsvg_state_reconstruct (RsvgState * state, RsvgNode * current)
 {
     if (current == NULL)
         return;
-    rsvg_state_reconstruct (state, current->parent);
+    rsvg_state_reconstruct (state, rsvg_node_get_parent (current));
     rsvg_state_inherit (state, rsvg_node_get_state (current));
 }