bb_xget[pw/gr]nam were horribly misnamed - fixed.
uidgid_get -> get_uidgid, add additional param
(numeric_ok). Make chown use it.
chown: fix "chown user: ...."
install: fix incorrect use of bb_xget[pw/gr]nam
diff --git a/libpwdgrp/uidgid_get.c b/libpwdgrp/uidgid_get.c
index a2d02a8..32cbd21 100644
--- a/libpwdgrp/uidgid_get.c
+++ b/libpwdgrp/uidgid_get.c
@@ -1,26 +1,47 @@
 #include "busybox.h"
 
-unsigned uidgid_get(struct bb_uidgid_t *u, const char *ug /*, unsigned dogrp */)
+int get_uidgid(struct bb_uidgid_t *u, const char *ug, int numeric_ok)
 {
 	struct passwd *pwd;
 	struct group *gr;
-	const char *g;
+	char *user, *group;
+	unsigned n;
 
-	/* g = 0; if (dogrp) g = strchr(ug, ':'); */
-	g = strchr(ug, ':');
-	if (g) {
-		int sz = (++g) - ug;
-		char buf[sz];
-		safe_strncpy(buf, ug, sz);
-		pwd = getpwnam(buf);
-	} else
-		pwd = getpwnam(ug);
+	user = (char*)ug;
+	group = strchr(ug, ':');
+	if (group) {
+		int sz = (++group) - ug;
+		user = alloca(sz);
+		/* copies sz-1 bytes, stores terminating '\0' */
+		safe_strncpy(user, ug, sz);
+	}
+	if (numeric_ok) {
+		n = bb_strtou(user, NULL, 10);
+		if (!errno) {
+			u->uid = n;
+			pwd = getpwuid(n);
+			/* If we have e.g. "500" string without user */
+			/* with uid 500 in /etc/passwd, we set gid == uid */
+			u->gid = pwd ? pwd->pw_gid : n;
+			goto skip;
+		}
+	}
+	pwd = getpwnam(user);
 	if (!pwd)
 		return 0;
 	u->uid = pwd->pw_uid;
 	u->gid = pwd->pw_gid;
-	if (g) {
-		gr = getgrnam(g);
+
+ skip:
+	if (group) {
+		if (numeric_ok) {
+			n = bb_strtou(group, NULL, 10);
+			if (!errno) {
+				u->gid = n;
+				return 1;
+			}
+		}
+		gr = getgrnam(group);
 		if (!gr) return 0;
 		u->gid = gr->gr_gid;
 	}
@@ -33,16 +54,16 @@
 {
 	unsigned u;
 	struct bb_uidgid_t ug;
-	u = uidgid_get(&ug, "apache");
+	u = get_uidgid(&ug, "apache", 0);
 	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
 	ug.uid = ug.gid = 1111;
-	u = uidgid_get(&ug, "apache");
+	u = get_uidgid(&ug, "apache", 0);
 	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
 	ug.uid = ug.gid = 1111;
-	u = uidgid_get(&ug, "apache:users");
+	u = get_uidgid(&ug, "apache:users", 0);
 	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
 	ug.uid = ug.gid = 1111;
-	u = uidgid_get(&ug, "apache:users");
+	u = get_uidgid(&ug, "apache:users", 0);
 	printf("%u = %u:%u\n", u, ug.uid, ug.gid);
 	return 0;
 }