Fix parsing of ambiguous options, the whole loop must be processed.

From FreeBSD.  OK miod@

src/lib/libc/stdlib/getopt_long.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: getopt_long.c,v 1.25 2011/03/05 22:10:11 guenther Exp $	*/
+/*	$OpenBSD: getopt_long.c,v 1.26 2013/06/08 22:47:56 millert Exp $	*/
 /*	$NetBSD: getopt_long.c,v 1.15 2002/01/31 22:43:40 tv Exp $	*/
 
 /*
@@ -77,7 +77,7 @@ char    *optarg;		/* argument associated with option */
 static int getopt_internal(int, char * const *, const char *,
 			   const struct option *, int *, int);
 static int parse_long_options(char * const *, const char *,
-			      const struct option *, int *, int);
+			      const struct option *, int *, int, int);
 static int gcd(int, int);
 static void permute_args(int, int, int, char * const *);
 
@@ -157,14 +157,16 @@ permute_args(int panonopt_start, int panonopt_end, int opt_end,
  */
 static int
 parse_long_options(char * const *nargv, const char *options,
-	const struct option *long_options, int *idx, int short_too)
+	const struct option *long_options, int *idx, int short_too, int flags)
 {
 	char *current_argv, *has_equal;
 	size_t current_argv_len;
-	int i, match;
+	int i, match, exact_match, second_partial_match;
 
 	current_argv = place;
 	match = -1;
+	exact_match = 0;
+	second_partial_match = 0;
 
 	optind++;
 
@@ -184,6 +186,7 @@ parse_long_options(char * const *nargv, const char *options,
 		if (strlen(long_options[i].name) == current_argv_len) {
 			/* exact match */
 			match = i;
+			exact_match = 1;
 			break;
 		}
 		/*
@@ -193,16 +196,20 @@ parse_long_options(char * const *nargv, const char *options,
 		if (short_too && current_argv_len == 1)
 			continue;
 
-		if (match == -1)	/* partial match */
+		if (match == -1)	/* first partial match */
 			match = i;
-		else {
-			/* ambiguous abbreviation */
-			if (PRINT_ERROR)
-				warnx(ambig, (int)current_argv_len,
-				     current_argv);
-			optopt = 0;
-			return (BADCH);
-		}
+		else if ((flags & FLAG_LONGONLY) ||
+		    long_options[i].has_arg != long_options[match].has_arg ||
+		    long_options[i].flag != long_options[match].flag ||
+		    long_options[i].val != long_options[match].val)
+			second_partial_match = 1;
+	}
+	if (!exact_match && second_partial_match) {
+		/* ambiguous abbreviation */
+		if (PRINT_ERROR)
+			warnx(ambig, (int)current_argv_len, current_argv);
+		optopt = 0;
+		return (BADCH);
 	}
 	if (match != -1) {		/* option found */
 		if (long_options[match].has_arg == no_argument
@@ -398,7 +405,7 @@ start:
 			short_too = 1;		/* could be short option too */
 
 		optchar = parse_long_options(nargv, options, long_options,
-		    idx, short_too);
+		    idx, short_too, flags);
 		if (optchar != -1) {
 			place = EMSG;
 			return (optchar);
@@ -435,7 +442,7 @@ start:
 		} else				/* white space */
 			place = nargv[optind];
 		optchar = parse_long_options(nargv, options, long_options,
-		    idx, 0);
+		    idx, 0, flags);
 		place = EMSG;
 		return (optchar);
 	}