[gnome-builder/wip/chergert/bug1] debugger: only clear debugger when new instance is set

[Christian Hergert <chergert src gnome org>]

commit 5b4af860f8f6f9b9871f5b5dd9440d6672e2129a
Author: Christian Hergert <chergert redhat com>
Date:   Mon Aug 28 12:25:17 2017 -0700

    debugger: only clear debugger when new instance is set
    
    If we are clearing the old debugger because it ended, keep the log alive
    for the user to potentially glean some insight.

 libide/debugger/ide-debugger-perspective.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/libide/debugger/ide-debugger-perspective.c b/libide/debugger/ide-debugger-perspective.c
index 9223b8f..e8ae7fe 100644
--- a/libide/debugger/ide-debugger-perspective.c
+++ b/libide/debugger/ide-debugger-perspective.c
@@ -136,8 +136,14 @@ ide_debugger_perspective_set_debugger (IdeDebuggerPerspective *self,
 
   if (g_set_object (&self->debugger, debugger))
     {
+      /* Clear the log if this is a new debugger instance,
+       * otherwise allow the user to read the backlog in case
+       * there was something useful for debugging.
+       */
+      if (debugger != NULL)
+        gtk_text_buffer_set_text (self->log_buffer, "", 0);
+
       dzl_signal_group_set_target (self->debugger_signals, debugger);
-      gtk_text_buffer_set_text (self->log_buffer, "", 0);
       g_object_notify_by_pspec (G_OBJECT (self), properties [PROP_DEBUGGER]);
     }