Problem report #133: base/src/emacs/src/font.c (font_range); FORWARD_NULL

[Dan Nicolaescu]

CID: 133
Checker: FORWARD_NULL (help)
File: base/src/emacs/src/font.c
Function: font_range
Description: Variable "face" tracked as NULL was passed to a function
that dereferences it.

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

3684          if (! face)
3685            {
3686              int face_id;
3687    
3688              face_id = face_at_buffer_position (w, pos, 0, 0, &ignore, 
*limit, 0);

At conditional (2): "face_id < (((0), ((w)->frame & -8))->face_cache)->used" 
taking false path

3689              face = FACE_FROM_ID (XFRAME (w->frame), face_id);
3690            }
3691        }
3692      else
3693        {
3694          font_assert (face);
3695          pos_byte = string_char_to_byte (string, pos);
3696        }
3697    
3698      start = pos, start_byte = pos_byte;

At conditional (3): "pos < *limit" taking true path

3699      while (pos < *limit)
3700        {
3701          Lisp_Object category;
3702    

At conditional (4): "string == Qnil" taking true path

3703          if (NILP (string))

At conditional (5): "pos_byte >= ((current_buffer)->text)->gpt_byte" taking 
true path
At conditional (6): "*(ptr + 0) & 128 == 0" taking true path
At conditional (7): "0" taking false path

3704            FETCH_CHAR_ADVANCE_NO_CHECK (c, pos, pos_byte);
3705          else
3706            FETCH_STRING_CHAR_ADVANCE_NO_CHECK (c, string, pos, pos_byte);

At conditional (8): "font_object == Qnil" taking true path

3707          if (NILP (font_object))
3708            {

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

3709              font_object = font_for_char (face, c, pos - 1, string);
3710              if (NILP (font_object))
3711                return Qnil;
3712              continue;
3713            }
3714    
3715          category = CHAR_TABLE_REF (Vunicode_category_table, c);
3716          if (! EQ (category, QCf)
3717              && font_encode_char (font_object, c) == FONT_INVALID_CODE)
3718            {

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

3719              Lisp_Object f = font_for_char (face, c, pos - 1, string);
3720              EMACS_INT i, i_byte;
3721