[librsvg] rsvg_drawing_ctx_pop_bounding_box(): Don't leak the old bbox

[Federico Mena Quintero <federico src gnome org>]

commit abe58904ab153ff4e60d2f0df192291acaa4012a
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri Jun 15 18:44:25 2018 -0500

    rsvg_drawing_ctx_pop_bounding_box(): Don't leak the old bbox

 librsvg/rsvg-drawing-ctx.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/librsvg/rsvg-drawing-ctx.c b/librsvg/rsvg-drawing-ctx.c
index 89d78445..379b75c5 100644
--- a/librsvg/rsvg-drawing-ctx.c
+++ b/librsvg/rsvg-drawing-ctx.c
@@ -162,6 +162,8 @@ void
 rsvg_drawing_ctx_pop_bounding_box (RsvgDrawingCtx *ctx)
 {
     rsvg_bbox_insert ((RsvgBbox *) ctx->bb_stack->data, ctx->bbox);
+    rsvg_bbox_free (ctx->bbox);
+
     ctx->bbox = (RsvgBbox *) ctx->bb_stack->data;
     ctx->bb_stack = g_list_delete_link (ctx->bb_stack, ctx->bb_stack);
 }