Make NULL a (void*)0 whereever possible, and fix the warnings(-Werror)

that this provokes. "Wherever possible" means "In the kernel OR NOT
C++" (implying C).

There are places where (void *) pointers are not valid, such as for
function pointers, but in the special case of (void *)0, agreement
settles on it being OK.

Most of the fixes were NULL where an integer zero was needed; many
of the fixes were NULL where ascii <nul> ('\0') was needed, and a
few were just "other".

Tested on: i386 sparc64

4 files changed, 8 insertions, 8 deletions

diff --git a/lib/libc/gen/dlfcn.c b/lib/libc/gen/dlfcn.c
index 25aa945..be58e28 100644
--- a/lib/libc/gen/dlfcn.c
+++ b/lib/libc/gen/dlfcn.c
@@ -109,7 +109,7 @@ int
 dlinfo(void * __restrict handle, int request, void * __restrict p)
 {
 	_rtld_error(sorry);
-	return NULL;
+	return 0;
 }
 
 #pragma weak _rtld_thread_init
diff --git a/lib/libc/gen/getpwent.c b/lib/libc/gen/getpwent.c
index ed65ad8..d0e4bf3 100644
--- a/lib/libc/gen/getpwent.c
+++ b/lib/libc/gen/getpwent.c
@@ -1624,7 +1624,7 @@ docompat:
 			case '@':
 				setnetgrent(&pw_name[2]);
 				while (getnetgrent(&host, &user, &domain) !=
-				    NULL) {
+				    0) {
 					if (user != NULL && user[0] != '\0')
 						compat_exclude(user,
 						    &st->exclude);
diff --git a/lib/libc/net/gethostbydns.c b/lib/libc/net/gethostbydns.c
index 82f5152..534073a 100644
--- a/lib/libc/net/gethostbydns.c
+++ b/lib/libc/net/gethostbydns.c
@@ -591,11 +591,11 @@ _dns_gethostbyname(void *rval, void *cb_data, va_list ap)
 	if (n < 0) {
 		free(buf);
 		dprintf("res_search failed (%d)\n", n);
-		return (NULL);
+		return (0);
 	} else if (n > sizeof(buf->buf)) {
 		free(buf);
 		dprintf("static buffer is too small (%d)\n", n);
-		return (NULL);
+		return (0);
 	}
 	*(struct hostent **)rval = gethostanswer(buf, n, name, type);
 	free(buf);
diff --git a/lib/libc/rpc/getnetconfig.c b/lib/libc/rpc/getnetconfig.c
index dae03b8..ea140d4 100644
--- a/lib/libc/rpc/getnetconfig.c
+++ b/lib/libc/rpc/getnetconfig.c
@@ -684,11 +684,11 @@ struct netconfig	*ncp;
      */
     *p = *ncp;
     p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);
-    tmp = strchr(tmp, NULL) + 1;
+    tmp = strchr(tmp, '\0') + 1;
     p->nc_protofmly = (char *)strcpy(tmp,ncp->nc_protofmly);
-    tmp = strchr(tmp, NULL) + 1;
+    tmp = strchr(tmp, '\0') + 1;
     p->nc_proto = (char *)strcpy(tmp,ncp->nc_proto);
-    tmp = strchr(tmp, NULL) + 1;
+    tmp = strchr(tmp, '\0') + 1;
     p->nc_device = (char *)strcpy(tmp,ncp->nc_device);
     p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));
     if (p->nc_lookups == NULL) {
@@ -696,7 +696,7 @@ struct netconfig	*ncp;
 	return(NULL);
     }
     for (i=0; i < p->nc_nlookups; i++) {
-    	tmp = strchr(tmp, NULL) + 1;
+    	tmp = strchr(tmp, '\0') + 1;
     	p->nc_lookups[i] = (char *)strcpy(tmp,ncp->nc_lookups[i]);
     }
     return(p);