Problem report #12

Problem report #12

[Dan Nicolaescu]

ERROR
CID: 12
Checker: FORWARD_NULL (help)
File: emacs/src/dispnew.c
Function: adjust_glyph_matrix
Description: Variable "w" tracked as NULL was dereferenced.

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

631  	  if (w)
632  	    {
633  	      window_box (w, -1, 0, 0, &window_width, &window_height);
634  	
635  	      header_line_p = WINDOW_WANTS_HEADER_LINE_P (w);
636  	      header_line_changed_p = header_line_p != matrix->header_line_p;
637  	    }
638  	  matrix->header_line_p = header_line_p;
639  	
640  	  /* If POOL is null, MATRIX is a window matrix for window-based redisplay.
641  	     Do nothing if MATRIX' size, position, vscroll, and marginal areas
642  	     haven't changed.  This optimization is important because preserving
643  	     the matrix means preventing redisplay.  */

At conditional (2): "(matrix)->pool == 0" taking true path

644  	  if (matrix->pool == NULL)
645  	    {

Event var_deref_op: Variable "w" tracked as NULL was dereferenced.
Also see events: [var_compare_op]

646  	      left = margin_glyphs_to_reserve (w, dim.width, w->left_margin_cols);
647  	      right = margin_glyphs_to_reserve (w, dim.width, w->right_margin_cols);
648  	      xassert (left >= 0 && right >= 0);
649  	      marginal_areas_changed_p = (left != matrix->left_margin_glyphs
650  					  || right != matrix->right_margin_glyphs);

Problem report #12

[Dan Nicolaescu]

CID: 12
Checker: FORWARD_NULL (help)
File: emacs/src/dispnew.c
Function: adjust_glyph_matrix
Description: Variable "w" tracked as NULL was dereferenced.

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

631  	  if (w)
632  	    {
633  	      window_box (w, -1, 0, 0, &window_width, &window_height);
634  	
635  	      header_line_p = WINDOW_WANTS_HEADER_LINE_P (w);
636  	      header_line_changed_p = header_line_p != matrix->header_line_p;
637  	    }
638  	  matrix->header_line_p = header_line_p;
639  	
640  	  /* If POOL is null, MATRIX is a window matrix for window-based redisplay.
641  	     Do nothing if MATRIX' size, position, vscroll, and marginal areas
642  	     haven't changed.  This optimization is important because preserving
643  	     the matrix means preventing redisplay.  */

At conditional (2): "(matrix)->pool == 0" taking true path

644  	  if (matrix->pool == NULL)
645  	    {

Event var_deref_op: Variable "w" tracked as NULL was dereferenced.
Also see events: [var_compare_op]

646  	      left = margin_glyphs_to_reserve (w, dim.width, w->left_margin_cols);
647  	      right = margin_glyphs_to_reserve (w, dim.width, w->right_margin_cols);
64

Re: Problem report #12

[Stuart D. Herring]

> 640  	  /* If POOL is null, MATRIX is a window matrix for window-based
> redisplay.
> 641  	     Do nothing if MATRIX' size, position, vscroll, and marginal
> areas
> 642  	     haven't changed.  This optimization is important because
> preserving
> 643  	     the matrix means preventing redisplay.  */
>
> At conditional (2): "(matrix)->pool == 0" taking true path

(Disclaimer: I know nothing about redisplay.)
See comment: w is only NULL if we're handling a frame matrix, not a window
matrix.  So matrix should have a pool, and this code path is dead.  No
bug.

Davis

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