Date: Wed, 8 Jun 1994 09:52:32 -0400
From: emory!cc.gatech.edu!arnold (Arnold Robbins)
Subject: unofficial fix for string  concatenation bug in gawk

*** eval.c.orig	Tue May 10 21:58:13 1994
--- eval.c	Tue Jun  7 18:30:46 1994
***************
*** 499,512 ****

  	case Node_concat:
  		{
! #define	STACKSIZE	10
! 		NODE *treelist[STACKSIZE+1];
! 		NODE *strlist[STACKSIZE+1];
  		register NODE **treep;
  		register NODE **strp;
  		register size_t len;
  		char *str;
  		register char *dest;

  		/*
  		 * This is an efficiency hack for multiple adjacent string
--- 499,513 ----

  	case Node_concat:
  		{
! 		NODE **treelist;
! 		NODE **strlist;
! 		NODE *save_tree;
  		register NODE **treep;
  		register NODE **strp;
  		register size_t len;
  		char *str;
  		register char *dest;
+ 		int count;

  		/*
  		 * This is an efficiency hack for multiple adjacent string
***************
*** 516,527 ****
  		 * descend to lowest (first) node, accumulating nodes
  		 * to evaluate to strings as we go.
  		 */
  		treep = treelist;
! 		while (tree->type == Node_concat) {
  			*treep++ = tree->rnode;
  			tree = tree->lnode;
- 			if (treep == &treelist[STACKSIZE])
- 				break;
  		}
  		*treep = tree;
  		/*
--- 517,542 ----
  		 * descend to lowest (first) node, accumulating nodes
  		 * to evaluate to strings as we go.
  		 */
+
+ 		/*
+ 		 * But first, no arbitrary limits. Count the number of
+ 		 * nodes and malloc the treelist and strlist arrays.
+ 		 * There will be count + 1 items to concatenate. We
+ 		 * also leave room for an extra pointer at the end to
+ 		 * use as a sentinel.  Thus, start count at 2.
+ 		 */
+ 		save_tree = tree;
+ 		for (count = 2; tree && tree->type == Node_concat; tree = tree->lnode)
+ 			count++;
+ 		tree = save_tree;
+ 		emalloc(treelist, NODE **, sizeof(NODE *) * count, "tree_eval");
+ 		emalloc(strlist, NODE **, sizeof(NODE *) * count, "tree_eval");
+
+ 		/* Now, here we go. */
  		treep = treelist;
! 		while (tree && tree->type == Node_concat) {
  			*treep++ = tree->rnode;
  			tree = tree->lnode;
  		}
  		*treep = tree;
  		/*
***************
*** 549,554 ****
--- 564,572 ----
  		}
  		r = make_str_node(str, len, ALREADY_MALLOCED);
  		r->flags |= TEMP;
+
+ 		free(strlist);
+ 		free(treelist);
  		}
  		return r;