🚀 go-pugleaf

To: bug-bash@ai.mit.edu

BASH version:	1.02
Machine:	Sun 3/160
OpSys:		SunOS 3.2 (4.2BSD)
Compiler:	Sun's native cc

------------------------------------------------------------
Description of bug:

Hitting ^D at the beginning of line results in the
following message:

Segmentation fault (core dumped)

and the shell crashes. This seems to be independent of the
value of 'IGNOREEOF' and 'ignoreeof'.

------------------------------------------------------------
Probable Reason:

I ran BASH in dbx, and found out that 'readline' returns EOF
coerced to a (char *) on its second invocation after it has
seen a valid EOF. On the other hand, 'yy_readline_get' never checks
if the value that 'readline' returns in 'current_readline_line'
is a valid pointer. When it gets to 'strlen' in the 'xrealloc'
call, BASH bombs out.

------------------------------------------------------------
My Fix:

I edited 'parse.y' to include a statement that checks if
'current_readline_line' is (char *) EOF:

08:16:45 pogo(6) diff -c parse.y parse.y~
*** parse.y     Mon Jul 17 08:16:44 1989
--- parse.y~    Mon Jul 17 08:05:13 1989
***************
*** 429,439 ****
        else
        current_readline_line = readline (current_readline_prompt);
  
-       if (current_readline_line == (char *) EOF) {
-                 current_readline_line = (char *)NULL;
-                 return (EOF);
-       }
- 
        current_readline_line_index = 0;
        current_readline_line =
        (char *)xrealloc (current_readline_line,
--- 429,434 ----
08:16:50 pogo(7)

------------------------------------------------------------

I have also seen erratic behaviour on ^D on a Compaq 386 running 
System V, but I haven't had time to look at it in great detail.