[evolution] Add e_activity_get_last_known_text().

[Matthew Barnes <mbarnes src gnome org>]

commit 682328cded9d509f121fcd0fc550919e9532ffb9
Author: Matthew Barnes <mbarnes redhat com>
Date:   Sat Jul 6 11:42:41 2013 -0400

    Add e_activity_get_last_known_text().
    
    Evolution is still occasionally getting stuck on shutdown, and although
    the evolution-shell log domain shows debug messages for activities that
    are preventing shutdown, they frequently look like this:
    
    (evolution:13534): evolution-shell-DEBUG: 5 active 'mail' activities:
    (evolution:13534): evolution-shell-DEBUG: * (no description)
    (evolution:13534): evolution-shell-DEBUG: * (no description)
    (evolution:13534): evolution-shell-DEBUG: * (no description)
    (evolution:13534): evolution-shell-DEBUG: * (no description)
    (evolution:13534): evolution-shell-DEBUG: * (no description)
    
    I think the lack of descriptions is from CamelOperations popping all
    their pushed messages, which is correct behavior but doesn't help us
    debug the problem.
    
    e_activity_get_last_known_text() returns the most recent _non-empty_
    text value set on the EActivity.  So our debug message can fall back
    to that if the EActivity has no description at shutdown:
    
    (evolution:13534): evolution-shell-DEBUG: * (was "blah, blah, blah")

 .../evolution-util/evolution-util-sections.txt     |    1 +
 e-util/e-activity.c                                |   32 ++++++++++++++++++++
 e-util/e-activity.h                                |    1 +
 shell/e-shell-backend.c                            |    6 ++++
 4 files changed, 40 insertions(+), 0 deletions(-)
---
diff --git a/doc/reference/evolution-util/evolution-util-sections.txt 
b/doc/reference/evolution-util/evolution-util-sections.txt
index 7ea0569..8e0c917 100644
--- a/doc/reference/evolution-util/evolution-util-sections.txt
+++ b/doc/reference/evolution-util/evolution-util-sections.txt
@@ -43,6 +43,7 @@ e_activity_get_state
 e_activity_set_state
 e_activity_get_text
 e_activity_set_text
+e_activity_get_last_known_text
 e_activity_handle_cancellation
 <SUBSECTION Standard>
 E_ACTIVITY
diff --git a/e-util/e-activity.c b/e-util/e-activity.c
index 87b8449..e3beb59 100644
--- a/e-util/e-activity.c
+++ b/e-util/e-activity.c
@@ -37,6 +37,7 @@
 #include <stdarg.h>
 #include <glib/gi18n.h>
 #include <camel/camel.h>
+#include <libedataserver/libedataserver.h>
 
 #include "e-util-enumtypes.h"
 
@@ -51,6 +52,7 @@ struct _EActivityPrivate {
 
        gchar *icon_name;
        gchar *text;
+       gchar *last_known_text;
        gdouble percent;
 
        /* Whether to emit a runtime warning if we
@@ -214,6 +216,7 @@ activity_finalize (GObject *object)
 
        g_free (priv->icon_name);
        g_free (priv->text);
+       g_free (priv->last_known_text);
 
        /* Chain up to parent's finalize() method. */
        G_OBJECT_CLASS (e_activity_parent_class)->finalize (object);
@@ -726,6 +729,8 @@ void
 e_activity_set_text (EActivity *activity,
                      const gchar *text)
 {
+       gchar *last_known_text = NULL;
+
        g_return_if_fail (E_IS_ACTIVITY (activity));
 
        if (g_strcmp0 (activity->priv->text, text) == 0)
@@ -734,10 +739,37 @@ e_activity_set_text (EActivity *activity,
        g_free (activity->priv->text);
        activity->priv->text = g_strdup (text);
 
+       /* See e_activity_get_last_known_text(). */
+       last_known_text = e_util_strdup_strip (text);
+       if (last_known_text != NULL) {
+               g_free (activity->priv->last_known_text);
+               activity->priv->last_known_text = last_known_text;
+       }
+
        g_object_notify (G_OBJECT (activity), "text");
 }
 
 /**
+ * e_activity_get_last_known_text:
+ * @activity: an #EActivity
+ *
+ * Returns the last non-empty #EActivity:text value, so it's possible to
+ * identify what the @activity <emphasis>was</emphasis> doing even if it
+ * currently has no description.
+ *
+ * Mostly useful for debugging.
+ *
+ * Returns: a descriptive message, or %NULL
+ **/
+const gchar *
+e_activity_get_last_known_text (EActivity *activity)
+{
+       g_return_val_if_fail (E_IS_ACTIVITY (activity), NULL);
+
+       return activity->priv->last_known_text;
+}
+
+/**
  * e_activity_handle_cancellation:
  * @activity: an #EActivity
  * @error: a #GError, or %NULL
diff --git a/e-util/e-activity.h b/e-util/e-activity.h
index 9309fe1..1c2cc4e 100644
--- a/e-util/e-activity.h
+++ b/e-util/e-activity.h
@@ -90,6 +90,7 @@ void          e_activity_set_state            (EActivity *activity,
 const gchar *  e_activity_get_text             (EActivity *activity);
 void           e_activity_set_text             (EActivity *activity,
                                                 const gchar *text);
+const gchar *  e_activity_get_last_known_text  (EActivity *activity);
 gboolean       e_activity_handle_cancellation  (EActivity *activity,
                                                 const GError *error);
 
diff --git a/shell/e-shell-backend.c b/shell/e-shell-backend.c
index 5f7666b..e4926c5 100644
--- a/shell/e-shell-backend.c
+++ b/shell/e-shell-backend.c
@@ -105,12 +105,18 @@ shell_backend_debug_list_activities (EShellBackend *shell_backend)
        for (link = head; link != NULL; link = g_list_next (link)) {
                EActivity *activity = E_ACTIVITY (link->data);
                gchar *description;
+               const gchar *was;
 
                description = e_activity_describe (activity);
+               was = e_activity_get_last_known_text (activity);
+
                if (description != NULL)
                        g_debug ("* %s", description);
+               else if (was != NULL)
+                       g_debug ("* (was \"%s\")", was);
                else
                        g_debug ("* (no description)");
+
                g_free (description);
        }
 }