[gnome-software] shell: fix signal blocking for search

[Kalev Lember <klember src gnome org>]

commit 2c560cd60648e0bab2b3625b5436d9327dae31bc
Author: Günther Wutz <info gunibert de>
Date:   Sun Sep 1 06:46:35 2019 +0200

    shell: fix signal blocking for search
    
    https://gitlab.gnome.org/GNOME/gnome-software/merge_requests/304
    
    Fixes https://gitlab.gnome.org/GNOME/gnome-software/issues/285

 src/gs-shell.c | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)
---
diff --git a/src/gs-shell.c b/src/gs-shell.c
index 7aa4be5b..eab11df1 100644
--- a/src/gs-shell.c
+++ b/src/gs-shell.c
@@ -452,6 +452,30 @@ gs_shell_plugin_events_restart_required_cb (GtkWidget *widget, GsShell *shell)
                g_warning ("failed to restart: %s", error->message);
 }
 
+/* this is basically a workaround for GtkSearchEntry. Due to delayed emission of the search-changed
+ * signal it can't be blocked during insertion of text into the entry. Therefore we block the
+ * precursor of that signal to be able to add text to the entry without firing the handlers
+ * connected to "search-changed"
+ */
+static void
+block_changed (GtkEditable *editable,
+               gpointer     user_data)
+{
+       g_signal_stop_emission_by_name (editable, "changed");
+}
+
+static void
+block_changed_signal (GtkSearchEntry *entry)
+{
+       g_signal_connect (entry, "changed", G_CALLBACK (block_changed), NULL);
+}
+
+static void
+unblock_changed_signal (GtkSearchEntry *entry)
+{
+       g_signal_handlers_disconnect_by_func (entry, G_CALLBACK (block_changed), NULL);
+}
+
 static void
 gs_shell_go_back (GsShell *shell)
 {
@@ -487,10 +511,10 @@ gs_shell_go_back (GsShell *shell)
 
                /* set the text in the entry and move cursor to the end */
                widget = GTK_WIDGET (gtk_builder_get_object (priv->builder, "entry_search"));
-               g_signal_handler_block (widget, priv->search_changed_id);
+               block_changed_signal (GTK_SEARCH_ENTRY (widget));
                gtk_entry_set_text (GTK_ENTRY (widget), entry->search);
                gtk_editable_set_position (GTK_EDITABLE (widget), -1);
-               g_signal_handler_unblock (widget, priv->search_changed_id);
+               unblock_changed_signal (GTK_SEARCH_ENTRY (widget));
 
                /* set the mode directly */
                gs_shell_change_mode (shell, entry->mode,