[epiphany/mcatanzaro/#1092] session: keep window alive when parsing session

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 79a3e159d15a97a02db62d2dd586144d3bb73fa3
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sun Feb 9 12:41:02 2020 -0600

    session: keep window alive when parsing session
    
    This is a second try at 32ecc861. This time, account for the fact that
    EphyWindow can be destroyed at the GTK level even if it still has an
    outstanding ref, and that will cause the last ref of the GtkNotebook to
    be destroyed. So instead of holding a ref, let's check for window
    destruction instead.
    
    Lastly, note 32ecc861 had introduced a memory leak, because
    context->window was set to NULL in session_end_element() without an
    unref.
    
    Fixes #1092

 src/ephy-session.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
---
diff --git a/src/ephy-session.c b/src/ephy-session.c
index 3a4139736..bb3a78e4c 100644
--- a/src/ephy-session.c
+++ b/src/ephy-session.c
@@ -1100,6 +1100,11 @@ session_parser_context_free (SessionParserContext *context)
 {
   g_object_unref (context->session);
 
+  if (context->window) {
+    /* This should only happen if the session state is malformed. */
+    g_signal_handlers_disconnect_by_data (context->window, context);
+  }
+
   g_free (context);
 }
 
@@ -1111,7 +1116,13 @@ session_parse_window (SessionParserContext  *context,
   GdkRectangle geometry = { -1, -1, 0, 0 };
   guint i;
 
+  if (context->window) {
+    /* This should only happen if the session state is malformed. */
+    return;
+  }
+
   context->window = ephy_window_new ();
+  g_signal_connect (context->window, "destroy", gtk_widget_destroyed, &context->window);
 
   for (i = 0; names[i]; i++) {
     gulong int_value;
@@ -1154,6 +1165,13 @@ session_parse_embed (SessionParserContext  *context,
   gboolean is_pin = FALSE;
   guint i;
 
+  if (!context->window) {
+    /* This can happen if the session is malformed, or if the window is
+     * destroyed before the session finishes loading.
+     */
+    return;
+  }
+
   notebook = ephy_window_get_notebook (context->window);
 
   for (i = 0; names[i]; i++) {
@@ -1283,6 +1301,13 @@ session_end_element (GMarkupParseContext  *ctx,
     GtkWidget *notebook;
     EphyEmbedShell *shell = ephy_embed_shell_get_default ();
 
+    if (!context->window) {
+      /* This can happen if the session is malformed, or if the window is
+       * destroyed before the session finishes loading.
+       */
+      return;
+    }
+
     notebook = ephy_window_get_notebook (context->window);
     gtk_notebook_set_current_page (GTK_NOTEBOOK (notebook), context->active_tab);
 
@@ -1297,6 +1322,7 @@ session_end_element (GMarkupParseContext  *ctx,
 
     ephy_embed_shell_restored_window (shell);
 
+    g_signal_handlers_disconnect_by_data (context->window, context);
     context->window = NULL;
     context->active_tab = 0;
     context->is_first_window = FALSE;