Re: bin/54574: usr.bin/make/parse.c $Id: 1.231 drops core on NetBSD-5.2 in realpath(3)

["Simon J. Gerraty" <sjg%juniper.net@localhost>]

John Nemeth <jnemeth%cue.bc.ca@localhost> wrote:
>       The realpath() function call first appeared in 4.4BSD.  In NetBSD 7.0 the
>       function was updated to accept a NULL pointer for the resolvedname
>       argument.
>  
>  POSIX says:
>  
>  If resolved_name is a null pointer, the behavior of realpath() is
>  implementation-defined.
>  
>  parse.c:1.231 in ParseVErrorInternal() calls realpath() with a null
>  pointer for resolved_name thus relying on the NetBSD 7.0 behaviour.
>  This is a portability bug.

The following should be safe:

Index: parse.c
===================================================================
RCS file: /cvsroot/src/usr.bin/make/parse.c,v
retrieving revision 1.232
diff -u -p -r1.232 parse.c
--- parse.c	9 Apr 2019 18:28:10 -0000	1.232
+++ parse.c	26 Sep 2019 06:31:44 -0000
@@ -669,6 +669,7 @@ static void
 ParseVErrorInternal(FILE *f, const char *cfname, size_t clineno, int type,
     const char *fmt, va_list ap)
 {
 	static Boolean fatal_warning_error_printed = FALSE;
+	char dirbuf[MAXPATHLEN+1];
 
 	(void)fprintf(f, "%s: ", progname);
@@ -688,7 +689,7 @@ ParseVErrorInternal(FILE *f, const char 
 			if (dir == NULL)
 				dir = ".";
 			if (*dir != '/') {
-				dir = cp2 = realpath(dir, NULL);
+				dir = cp2 = realpath(dir, dirbuf);
 				free(cp);
 				cp = cp2; /* cp2 set to NULL by Var_Value */
 			}