add more locks in view/textlist.c

no deadlock should be possible as of the current state of
things. When the textlist's lock is set the GUI lock is
never on.

Let's cross fingers that things don't change crazily in
the future...

common/utils/T/tracer/view/textlist.c

@@ -45,7 +45,6 @@ static void *textlist_thread(void *_this)
       _append(this, s, &deleted);
       free(s);
     }
-    if (pthread_mutex_unlock(&this->lock)) abort();
     if (dirty) {
       text_list_state(this->g, this->w, &visible_lines, &start_line,
           &number_of_lines);
@@ -58,6 +57,7 @@ static void *textlist_thread(void *_this)
       /* this call is not necessary, but if things change in text_list... */
       widget_dirty(this->g, this->w);
     }
+    if (pthread_mutex_unlock(&this->lock)) abort();
     sleepms(1000/this->refresh_rate);
   }
 
@@ -90,6 +90,8 @@ static void scroll(void *private, gui *g,
   int new_line;
   int inc;
 
+  if (pthread_mutex_lock(&this->lock)) abort();
+
   text_list_state(g, w, &visible_lines, &start_line, &number_of_lines);
   inc = 10;
   if (inc > visible_lines - 2) inc = visible_lines - 2;
@@ -107,6 +109,8 @@ static void scroll(void *private, gui *g,
     this->autoscroll = 0;
   else
     this->autoscroll = 1;
+
+  if (pthread_mutex_unlock(&this->lock)) abort();
 }
 
 static void click(void *private, gui *g,
@@ -116,7 +120,11 @@ static void click(void *private, gui *g,
   int *d = notification_data;
   int button = d[1];
 
+  if (pthread_mutex_lock(&this->lock)) abort();
+
   if (button == 1) this->autoscroll = 1 - this->autoscroll;
+
+  if (pthread_mutex_unlock(&this->lock)) abort();
 }
 
 view *new_textlist(int maxsize, float refresh_rate, gui *g, widget *w)