Problem report #20

[Dan Nicolaescu]

CID: 20
Checker: FORWARD_NULL (help)
File: emacs/src/insdel.c
Function: prepare_to_modify_buffer
Description: Variable "preserve_ptr" tracked as NULL was passed to a function 
that dereferences it.

Event var_compare_op: Added "preserve_ptr" due to comparison "preserve_ptr != 0"
Also see events: [var_deref_model]
At conditional (1): "preserve_ptr != 0" taking false path

2044          if (preserve_ptr)
2045            {
2046              Lisp_Object preserve_marker;
2047              struct gcpro gcpro1;
2048              preserve_marker = Fcopy_marker (make_number (*preserve_ptr), 
Qnil);
2049              GCPRO1 (preserve_marker);
2050              verify_interval_modification (current_buffer, start, end);
2051              *preserve_ptr = marker_position (preserve_marker);
2052              unchain_marker (XMARKER (preserve_marker));
2053              UNGCPRO;
2054            }
2055          else
2056            verify_interval_modification (current_buffer, start, end);
2057        }
2058    
2059    #ifdef CLASH_DETECTION

At conditional (2): "(current_buffer)->file_truename != Qnil" taking true path
At conditional (3): "(current_buffer)->filename != Qnil" taking true path
At conditional (4): "((current_buffer)->text)->save_modiff >= 
((current_buffer)->text)->modiff" taking true path

2060      if (!NILP (current_buffer->file_truename)
2061          /* Make binding buffer-file-name to nil effective.  */
2062          && !NILP (current_buffer->filename)
2063          && SAVE_MODIFF >= MODIFF)
2064        lock_file (current_buffer->file_truename);
2065    #else
2066      /* At least warn if this file has changed on disk since it was 
visited.  */
2067      if (!NILP (current_buffer->filename)
2068          && SAVE_MODIFF >= MODIFF
2069          && NILP (Fverify_visited_file_modtime (Fcurrent_buffer ()))
2070          && !NILP (Ffile_exists_p (current_buffer->filename)))
2071        call1 (intern ("ask-user-about-supersession-threat"),
2072               current_buffer->filename);
2073    #endif /* not CLASH_DETECTION */
2074    

Event var_deref_model: Variable "preserve_ptr" tracked as NULL was passed to a 
function that dereferences it. [model]
Also see events: [var_compare_op]

2075      signal_before_change (start, end, preserve_ptr);
2076