make: ensure ${.MAKE} works

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

This came up in a recent thread.

Anyone object?

--------------------8<--------------------
If argv[0] contains '/' but is not an absolute path,
use realpath() to resolve it for setting .MAKE

Index: main.c
===================================================================
RCS file: /cvsroot/src/usr.bin/make/main.c,v
retrieving revision 1.177
diff -u -p -r1.177 main.c
--- main.c      8 Apr 2010 17:41:29 -0000       1.177
+++ main.c      13 Apr 2010 20:59:35 -0000
@@ -895,8 +895,14 @@ main(int argc, char **argv)
         *      MFLAGS also gets initialized empty, for compatibility.
         */
        Parse_Init();
-       Var_Set("MAKE", argv[0], VAR_GLOBAL, 0);
-       Var_Set(".MAKE", argv[0], VAR_GLOBAL, 0);
+       if ((p1 = strchr(argv[0], '/')) && p1 != argv[0]) {
+               /* resolve to an absolute path */
+               p1 = realpath(argv[0], mdpath);
+       }
+       if (!p1)
+               p1 = argv[0];
+       Var_Set("MAKE", p1, VAR_GLOBAL, 0);
+       Var_Set(".MAKE", p1, VAR_GLOBAL, 0);
        Var_Set(MAKEFLAGS, "", VAR_GLOBAL, 0);
        Var_Set(MAKEOVERRIDES, "", VAR_GLOBAL, 0);
        Var_Set("MFLAGS", "", VAR_GLOBAL, 0);