Re: [RFA] breakpoint.c: Avoid double freeing in breakpoint_re_set_one

[Andrew Cagney <cagney at gnu dot org>]

> Anyway, I've committed the attached (slightly tweaked).

Doh! Try ...
2004-01-27  Paul N. Hilfinger  <hilfinger@gnat.com>
	
	* breakpoint.c (breakpoint_re_set_one): Set b->cond, b->val, and
	b->exp to NULL after freeing so that error during re-parsing or
	evaluation of expressions associated with breakpoint don't
	eventually lead to re-freeing of storage.
	Committed by Andrew Cagney.

Index: breakpoint.c
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.c,v
retrieving revision 1.151
diff -u -r1.151 breakpoint.c
--- breakpoint.c	27 Jan 2004 03:13:34 -0000	1.151
+++ breakpoint.c	28 Jan 2004 01:34:34 -0000
@@ -6970,12 +6970,22 @@
 
       /* So for now, just use a global context.  */
       if (b->exp)
-	xfree (b->exp);
+	{
+	  xfree (b->exp);
+	  /* Avoid re-freeing b->exp if an error during the call to
+             parse_expression.  */
+	  b->exp = NULL;
+	}
       b->exp = parse_expression (b->exp_string);
       b->exp_valid_block = innermost_block;
       mark = value_mark ();
       if (b->val)
-	value_free (b->val);
+	{
+	  value_free (b->val);
+	  /* Avoid re-freeing b->val if an error during the call to
+             evaluate_expression.  */
+	  b->val = NULL;
+	}
       b->val = evaluate_expression (b->exp);
       release_value (b->val);
       if (VALUE_LAZY (b->val) && breakpoint_enabled (b))
@@ -6985,7 +6995,12 @@
 	{
 	  s = b->cond_string;
 	  if (b->cond)
-	    xfree (b->cond);
+	    {
+	      xfree (b->cond);
+	      /* Avoid re-freeing b->exp if an error during the call
+		 to parse_exp_1.  */
+	      b->cond = NULL;
+	    }
 	  b->cond = parse_exp_1 (&s, (struct block *) 0, 0);
 	}
       if (breakpoint_enabled (b))