[gthumb] search: stop the previous search before starting the new one

[Paolo Bacchilega <paobac src gnome org>]

commit 73c8b9bc2b8cfd4f7520fbabe12817afbd2e2a9d
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Thu Dec 31 17:25:13 2020 +0100

    search: stop the previous search before starting the new one

 gthumb/gth-browser.c | 59 +++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 45 insertions(+), 14 deletions(-)
---
diff --git a/gthumb/gth-browser.c b/gthumb/gth-browser.c
index 81034e49..157adab2 100644
--- a/gthumb/gth-browser.c
+++ b/gthumb/gth-browser.c
@@ -161,6 +161,7 @@ struct _GthBrowserPrivate {
        gboolean           fast_file_type;
        gboolean           closing;
        GthTask           *task;
+       GthTask           *next_task;
        gulong             task_completed;
        gulong             task_progress;
        GList             *background_tasks;
@@ -4311,6 +4312,7 @@ gth_browser_init (GthBrowser *browser)
        browser->priv->task = NULL;
        browser->priv->task_completed = 0;
        browser->priv->task_progress = 0;
+       browser->priv->next_task = NULL;
        browser->priv->background_tasks = NULL;
        browser->priv->close_with_task = FALSE;
        browser->priv->load_data_queue = NULL;
@@ -5641,11 +5643,18 @@ task_data_new (GthBrowser   *browser,
 }
 
 
+static void
+_gth_browser_exec_foreground_task (GthBrowser   *browser,
+                                  GthTask      *task);
+
+
 static void
 foreground_task_completed_cb (GthTask    *task,
                              GError     *error,
                              GthBrowser *browser)
 {
+       g_return_if_fail (task == browser->priv->task);
+
        _gth_browser_remove_activity (browser);
 
        g_signal_handler_disconnect (browser->priv->task, browser->priv->task_completed);
@@ -5657,6 +5666,11 @@ foreground_task_completed_cb (GthTask    *task,
 
        g_object_unref (browser->priv->task);
        browser->priv->task = NULL;
+
+       if (browser->priv->next_task != NULL) {
+               _gth_browser_exec_foreground_task (browser, browser->priv->next_task);
+               _g_clear_object (&browser->priv->next_task);
+       }
 }
 
 
@@ -5672,6 +5686,27 @@ foreground_task_progress_cb (GthTask    *task,
 }
 
 
+static void
+_gth_browser_exec_foreground_task (GthBrowser   *browser,
+                                  GthTask      *task)
+{
+       g_return_if_fail (browser->priv->task == NULL);
+
+       browser->priv->task = g_object_ref (task);
+       browser->priv->task_completed = g_signal_connect (task,
+                                                         "completed",
+                                                         G_CALLBACK (foreground_task_completed_cb),
+                                                         browser);
+       browser->priv->task_progress = g_signal_connect (task,
+                                                        "progress",
+                                                        G_CALLBACK (foreground_task_progress_cb),
+                                                        browser);
+       _gth_browser_add_activity (browser);
+       gth_browser_update_sensitivity (browser);
+       gth_task_exec (browser->priv->task, NULL);
+}
+
+
 void
 gth_browser_exec_task (GthBrowser   *browser,
                       GthTask      *task,
@@ -5699,21 +5734,14 @@ gth_browser_exec_task (GthBrowser   *browser,
 
        /* foreground task */
 
-       if (browser->priv->task != NULL)
+       if (browser->priv->task != NULL) {
+               _g_object_unref (browser->priv->next_task);
+               browser->priv->next_task = g_object_ref (task);
                gth_task_cancel (task);
+               return;
+       }
 
-       browser->priv->task = g_object_ref (task);
-       browser->priv->task_completed = g_signal_connect (task,
-                                                         "completed",
-                                                         G_CALLBACK (foreground_task_completed_cb),
-                                                         browser);
-       browser->priv->task_progress = g_signal_connect (task,
-                                                        "progress",
-                                                        G_CALLBACK (foreground_task_progress_cb),
-                                                        browser);
-       _gth_browser_add_activity (browser);
-       gth_browser_update_sensitivity (browser);
-       gth_task_exec (browser->priv->task, NULL);
+       _gth_browser_exec_foreground_task (browser, task);
 }
 
 
@@ -6770,8 +6798,11 @@ _gth_browser_cancel (GthBrowser *browser,
                        gth_task_cancel (data->task);
        }
 
-       if ((browser->priv->task != NULL) && gth_task_is_running (browser->priv->task))
+       if ((browser->priv->task != NULL) && gth_task_is_running (browser->priv->task)) {
+               if (browser->priv->next_task != NULL)
+                       _g_clear_object (&browser->priv->next_task);
                gth_task_cancel (browser->priv->task);
+       }
 
        cancel_data->check_id = g_timeout_add (CHECK_CANCELLABLE_INTERVAL,
                                               check_cancellable_cb,