Ticket #2859 (mcedit ctags fix)

How to reproduce:

    on sources: ctags -R .
    with tags in current dir open any file (needn't be C source or headers)
    Alt- (i.e. alt minus or Esc '-')

Current result: sigsegv

Signed-off-by: Ilia Maslakov <il.smind@gmail.com>

src/editor/edit-impl.h

@@ -151,7 +151,7 @@ extern int enable_show_tabs_tws;
 
 extern edit_search_options_t edit_search_options;
 
-extern int edit_stack_iterator;
+extern unsigned int edit_stack_iterator;
 extern edit_stack_type edit_history_moveto[MAX_HISTORY_MOVETO];
 
 extern int option_line_state_width;

src/editor/edit.c

@@ -103,7 +103,7 @@ int show_right_margin = 0;
 const char *option_whole_chars_search = "0123456789abcdefghijklmnopqrstuvwxyz_";
 char *option_backup_ext = NULL;
 
-int edit_stack_iterator = 0;
+unsigned int edit_stack_iterator = 0;
 edit_stack_type edit_history_moveto[MAX_HISTORY_MOVETO];
 /* magic sequense for say than block is vertical */
 const char VERTICAL_MAGIC[] = { '\1', '\1', '\1', '\1', '\n' };

src/editor/editcmd.c

@@ -3492,7 +3492,8 @@ edit_load_back_cmd (WEdit * edit)
         return TRUE;
     }
 
-    if (edit_stack_iterator < 0)
+    /* we are in the bottom of the stack, NO WAY! */
+    if (edit_stack_iterator == 0)
         return FALSE;
 
     edit_stack_iterator--;