Rewrite locale loading procedures, so any load failure will not affect

currently cached data.  It allows a number of nice things, like: removing
fallback code from single locale loading, remove memory leak when LC_CTYPE
data loaded again and again, efficient cache use, not only for
setlocale(locale1); setlocale(locale1), but for setlocale(locale1);
setlocale("C"); setlocale(locale1) too (i.e.  data file loaded only once).

11 files changed, 259 insertions, 192 deletions

diff --git a/lib/libc/locale/collate.c b/lib/libc/locale/collate.c
index 83684d1..c7e6c12 100644
--- a/lib/libc/locale/collate.c
+++ b/lib/libc/locale/collate.c
@@ -40,68 +40,115 @@ __FBSDID("$FreeBSD$");
 
 #include "collate.h"
 #include "setlocale.h"
+#include "ldpart.h"
 
 #include "libc_private.h"
 
 int __collate_load_error = 1;
 int __collate_substitute_nontrivial;
-char __collate_version[STR_LEN];
+
 u_char __collate_substitute_table[UCHAR_MAX + 1][STR_LEN];
 struct __collate_st_char_pri __collate_char_pri_table[UCHAR_MAX + 1];
 struct __collate_st_chain_pri __collate_chain_pri_table[TABLE_SIZE];
 
-#define FREAD(a, b, c, d) \
-	do { \
-		if (fread(a, b, c, d) != c) { \
-			(void)fclose(d); \
-			return -1; \
-		} \
-	} while(0)
-
 void __collate_err(int ex, const char *f) __dead2;
 
 int
-__collate_load_tables(encoding)
-	char *encoding;
+__collate_load_tables(const char *encoding)
 {
-	char buf[PATH_MAX];
 	FILE *fp;
-	int i, save_load_error;
+	int i, saverr;
+	char collate_version[STR_LEN];
+	char buf[PATH_MAX];
+	char *TMP_substitute_table, *TMP_char_pri_table, *TMP_chain_pri_table;
+	static char collate_encoding[ENCODING_LEN + 1];
 
-	save_load_error = __collate_load_error;
-	__collate_load_error = 1;
-	if (!encoding) {
-		__collate_load_error = save_load_error;
-		return -1;
+	/* 'encoding' must be already checked. */
+	if (strcmp(encoding, "C") == 0 || strcmp(encoding, "POSIX") == 0) {
+		__collate_load_error = 1;
+		return (_LDP_CACHE);
 	}
-	if (!strcmp(encoding, "C") || !strcmp(encoding, "POSIX"))
-		return 0;
-	if (!_PathLocale) {
-		__collate_load_error = save_load_error;
-		return -1;
+
+	/*
+	 * If the locale name is the same as our cache, use the cache.
+	 */
+	if (strcmp(encoding, collate_encoding) == 0) {
+		__collate_load_error = 0;
+		return (_LDP_CACHE);
 	}
+
+	/*
+	 * Slurp the locale file into the cache.
+	 */
+
+	/* 'PathLocale' must be already set & checked. */
 	/* Range checking not needed, encoding has fixed size */
 	(void)strcpy(buf, _PathLocale);
 	(void)strcat(buf, "/");
 	(void)strcat(buf, encoding);
 	(void)strcat(buf, "/LC_COLLATE");
-	if ((fp = fopen(buf, "r")) == NULL) {
-		__collate_load_error = save_load_error;
-		return -1;
+	if ((fp = fopen(buf, "r")) == NULL)
+		return (_LDP_ERROR);
+
+	if ((TMP_substitute_table =
+	     malloc(sizeof(__collate_substitute_table))) == NULL) {
+		(void)fclose(fp);
+		errno = ENOMEM;
+		return (_LDP_ERROR);
 	}
-	FREAD(__collate_version, sizeof(__collate_version), 1, fp);
-	if (strcmp(__collate_version, COLLATE_VERSION) != 0) {
+	if ((TMP_char_pri_table =
+	     malloc(sizeof(__collate_char_pri_table))) == NULL) {
+		free(TMP_substitute_table);
 		(void)fclose(fp);
-		return -1;
+		errno = ENOMEM;
+		return (_LDP_ERROR);
 	}
-	FREAD(__collate_substitute_table, sizeof(__collate_substitute_table),
-	      1, fp);
-	FREAD(__collate_char_pri_table, sizeof(__collate_char_pri_table), 1,
-	      fp);
-	FREAD(__collate_chain_pri_table, sizeof(__collate_chain_pri_table), 1,
-	      fp);
+	if ((TMP_chain_pri_table =
+	     malloc(sizeof(__collate_chain_pri_table))) == NULL) {
+		free(TMP_substitute_table);
+		free(TMP_char_pri_table);
+		(void)fclose(fp);
+		errno = ENOMEM;
+		return (_LDP_ERROR);
+	}
+
+#define FREAD(a, b, c, d) \
+{ \
+	if (fread(a, b, c, d) != c) { \
+		saverr = errno; \
+		free(TMP_substitute_table); \
+		free(TMP_char_pri_table); \
+		free(TMP_chain_pri_table); \
+		(void)fclose(d); \
+		errno = saverr; \
+		return (_LDP_ERROR); \
+	} \
+}
+
+	FREAD(collate_version, sizeof(collate_version), 1, fp);
+	if (strcmp(collate_version, COLLATE_VERSION) != 0) {
+		free(TMP_substitute_table);
+		free(TMP_char_pri_table);
+		free(TMP_chain_pri_table);
+		(void)fclose(fp);
+		errno = EFTYPE;
+		return (_LDP_ERROR);
+	}
+	FREAD(TMP_substitute_table, sizeof(__collate_substitute_table), 1, fp);
+	FREAD(TMP_char_pri_table, sizeof(__collate_char_pri_table), 1, fp);
+	FREAD(TMP_chain_pri_table, sizeof(__collate_chain_pri_table), 1, fp);
 	(void)fclose(fp);
-	__collate_load_error = 0;
+
+	(void)strcpy(collate_encoding, encoding);
+	(void)memcpy(__collate_substitute_table, TMP_substitute_table,
+		     sizeof(__collate_substitute_table));
+	(void)memcpy(__collate_char_pri_table, TMP_char_pri_table,
+		     sizeof(__collate_char_pri_table));
+	(void)memcpy(__collate_chain_pri_table, TMP_chain_pri_table,
+		     sizeof(__collate_chain_pri_table));
+	free(TMP_substitute_table);
+	free(TMP_char_pri_table);
+	free(TMP_chain_pri_table);
 	
 	__collate_substitute_nontrivial = 0;
 	for (i = 0; i < UCHAR_MAX + 1; i++) {
@@ -111,8 +158,9 @@ __collate_load_tables(encoding)
 			break;
 		}
 	}
+	__collate_load_error = 0;
 
-	return 0;
+	return (_LDP_LOADED);
 }
 
 u_char *
@@ -152,8 +200,8 @@ __collate_lookup(t, len, prim, sec)
 
 	*len = 1;
 	*prim = *sec = 0;
-	for(p2 = __collate_chain_pri_table; p2->str[0]; p2++) {
-		if(strncmp(t, p2->str, strlen(p2->str)) == 0) {
+	for (p2 = __collate_chain_pri_table; p2->str[0]; p2++) {
+		if (strncmp(t, p2->str, strlen(p2->str)) == 0) {
 			*len = strlen(p2->str);
 			*prim = p2->prim;
 			*sec = p2->sec;
diff --git a/lib/libc/locale/collate.h b/lib/libc/locale/collate.h
index d8dd045..4a0eefb 100644
--- a/lib/libc/locale/collate.h
+++ b/lib/libc/locale/collate.h
@@ -48,7 +48,6 @@ struct __collate_st_chain_pri {
 
 extern int __collate_load_error;
 extern int __collate_substitute_nontrivial;
-extern char __collate_version[STR_LEN];
 extern u_char __collate_substitute_table[UCHAR_MAX + 1][STR_LEN];
 extern struct __collate_st_char_pri __collate_char_pri_table[UCHAR_MAX + 1];
 extern struct __collate_st_chain_pri __collate_chain_pri_table[TABLE_SIZE];
@@ -56,7 +55,7 @@ extern struct __collate_st_chain_pri __collate_chain_pri_table[TABLE_SIZE];
 __BEGIN_DECLS
 u_char	*__collate_strdup(u_char *);
 u_char	*__collate_substitute(const u_char *);
-int	__collate_load_tables(char *);
+int	__collate_load_tables(const char *);
 void	__collate_lookup(const u_char *, int *, int *, int *);
 int	__collate_range_cmp(int, int);
 #ifdef COLLATE_DEBUG
diff --git a/lib/libc/locale/euc.c b/lib/libc/locale/euc.c
index 9008a91..43194fa 100644
--- a/lib/libc/locale/euc.c
+++ b/lib/libc/locale/euc.c
@@ -63,40 +63,36 @@ _EUC_init(rl)
 	_RuneLocale *rl;
 {
 	_EucInfo *ei;
-	int x;
+	int x, new__mb_cur_max;
 	char *v, *e;
 
 	rl->sgetrune = _EUC_sgetrune;
 	rl->sputrune = _EUC_sputrune;
 
-	if (!rl->variable) {
-		free(rl);
+	if (rl->variable == NULL)
 		return (EFTYPE);
-	}
-	v = (char *) rl->variable;
+
+	v = (char *)rl->variable;
 
 	while (*v == ' ' || *v == '\t')
 		++v;
 
-	if ((ei = malloc(sizeof(_EucInfo))) == NULL) {
-		free(rl);
+	if ((ei = malloc(sizeof(_EucInfo))) == NULL)
 		return (ENOMEM);
-	}
-	__mb_cur_max = 0;
+
+	new__mb_cur_max = 0;
 	for (x = 0; x < 4; ++x) {
-		ei->count[x] = (int) strtol(v, &e, 0);
+		ei->count[x] = (int)strtol(v, &e, 0);
 		if (v == e || !(v = e)) {
-			free(rl);
 			free(ei);
 			return (EFTYPE);
 		}
-		if (__mb_cur_max < ei->count[x])
-			__mb_cur_max = ei->count[x];
+		if (new__mb_cur_max < ei->count[x])
+			new__mb_cur_max = ei->count[x];
 		while (*v == ' ' || *v == '\t')
 			++v;
-		ei->bits[x] = (int) strtol(v, &e, 0);
+		ei->bits[x] = (int)strtol(v, &e, 0);
 		if (v == e || !(v = e)) {
-			free(rl);
 			free(ei);
 			return (EFTYPE);
 		}
@@ -105,18 +101,13 @@ _EUC_init(rl)
 	}
 	ei->mask = (int)strtol(v, &e, 0);
 	if (v == e || !(v = e)) {
-		free(rl);
 		free(ei);
 		return (EFTYPE);
 	}
-	if (sizeof(_EucInfo) <= rl->variable_len) {
-		memcpy(rl->variable, ei, sizeof(_EucInfo));
-		free(ei);
-	} else {
-		rl->variable = ei;
-	}
+	rl->variable = ei;
 	rl->variable_len = sizeof(_EucInfo);
 	_CurrentRuneLocale = rl;
+	__mb_cur_max = new__mb_cur_max;
 	return (0);
 }
 
diff --git a/lib/libc/locale/ldpart.c b/lib/libc/locale/ldpart.c
index 0e276cf..1933312 100644
--- a/lib/libc/locale/ldpart.c
+++ b/lib/libc/locale/ldpart.c
@@ -42,7 +42,6 @@ __FBSDID("$FreeBSD$");
 #include "ldpart.h"
 
 static int split_lines(char *, const char *);
-static void set_from_buf(const char *, int, const char **);
 
 int
 __part_load_locale(const char *name,
@@ -53,35 +52,25 @@ __part_load_locale(const char *name,
 		int locale_buf_size_min,
 		const char **dst_localebuf)
 {
-	static char	locale_buf_C[] = "C";
-	static int	num_lines;
-	int             saverr;
-	int		fd;
-	char		*lbuf;
-	char		*p;
-	const char 	*plim;
-	char            filename[PATH_MAX];
+	int		saverr, fd, i, num_lines;
+	char		*lbuf, *p;
+	const char	*plim;
+	char		filename[PATH_MAX];
 	struct stat	st;
-	size_t		namesize;
-	size_t		bufsize;
-	int             save_using_locale;
-
-	save_using_locale = *using_locale;
-	*using_locale = 0;
+	size_t		namesize, bufsize;
 
 	/* 'name' must be already checked. */
-
-	if (!strcmp(name, "C") || !strcmp(name, "POSIX"))
-		return 0;
+	if (strcmp(name, "C") == 0 || strcmp(name, "POSIX") == 0) {
+		*using_locale = 0;
+		return (_LDP_CACHE);
+	}
 
 	/*
 	 * If the locale name is the same as our cache, use the cache.
 	 */
-	lbuf = locale_buf;
-	if (lbuf != NULL && strcmp(name, lbuf) == 0) {
-		set_from_buf(lbuf, num_lines, dst_localebuf);
+	if (locale_buf != NULL && strcmp(name, locale_buf) == 0) {
 		*using_locale = 1;
-		return 0;
+		return (_LDP_CACHE);
 	}
 
 	/*
@@ -90,16 +79,14 @@ __part_load_locale(const char *name,
 	namesize = strlen(name) + 1;
 
 	/* 'PathLocale' must be already set & checked. */
-
 	/* Range checking not needed, 'name' size is limited */
 	strcpy(filename, _PathLocale);
 	strcat(filename, "/");
 	strcat(filename, name);
 	strcat(filename, "/");
 	strcat(filename, category_filename);
-	fd = _open(filename, O_RDONLY);
-	if (fd < 0)
-		goto no_locale;
+	if ((fd = _open(filename, O_RDONLY)) < 0)
+		return (_LDP_ERROR);
 	if (_fstat(fd, &st) != 0)
 		goto bad_locale;
 	if (st.st_size <= 0) {
@@ -107,18 +94,15 @@ __part_load_locale(const char *name,
 		goto bad_locale;
 	}
 	bufsize = namesize + st.st_size;
-	locale_buf = NULL;
-	lbuf = (lbuf == NULL || lbuf == locale_buf_C) ?
-		malloc(bufsize) : reallocf(lbuf, bufsize);
-	if (lbuf == NULL)
+	if ((lbuf = malloc(bufsize)) == NULL) {
+		errno = ENOMEM;
 		goto bad_locale;
+	}
 	(void)strcpy(lbuf, name);
 	p = lbuf + namesize;
 	plim = p + st.st_size;
 	if (_read(fd, p, (size_t) st.st_size) != st.st_size)
 		goto bad_lbuf;
-	if (_close(fd) != 0)
-		goto bad_lbuf;
 	/*
 	 * Parse the locale file into localebuf.
 	 */
@@ -133,37 +117,37 @@ __part_load_locale(const char *name,
 		num_lines = locale_buf_size_min;
 	else {
 		errno = EFTYPE;
-		goto reset_locale;
+		goto bad_lbuf;
 	}
-	set_from_buf(lbuf, num_lines, dst_localebuf);
+	(void)_close(fd);
 	/*
 	 * Record the successful parse in the cache.
 	 */
+	if (locale_buf != NULL)
+		free(locale_buf);
 	locale_buf = lbuf;
-
+	for (p = locale_buf, i = 0; i < num_lines; i++)
+		dst_localebuf[i] = (p += strlen(p) + 1);
+	for (i = num_lines; i < locale_buf_size_max; i++)
+		dst_localebuf[i] = NULL;
 	*using_locale = 1;
 
-	return 0;
+	return (_LDP_LOADED);
 
-reset_locale:
-	locale_buf = locale_buf_C;
-	save_using_locale = 0;
 bad_lbuf:
-	saverr = errno; 
-	free(lbuf); 
+	saverr = errno;
+	free(lbuf);
 	errno = saverr;
 bad_locale:
-	saverr = errno; 
-	(void)_close(fd); 
+	saverr = errno;
+	(void)_close(fd);
 	errno = saverr;
-no_locale:
-	*using_locale = save_using_locale;
 
-	return -1;
+	return (_LDP_ERROR);
 }
 
 static int
-split_lines(char *p, const char *plim) 
+split_lines(char *p, const char *plim)
 {
 	int i;
 
@@ -174,13 +158,3 @@ split_lines(char *p, const char *plim)
 	return (i);
 }
 
-static void
-set_from_buf(const char *p, int num_lines, const char **dst_localebuf) {
-
-	const char **ap;
-	int i;
-
-	for (ap = dst_localebuf, i = 0; i < num_lines; ++ap, ++i)
-		*ap = p += strlen(p) + 1;
-}
-
diff --git a/lib/libc/locale/ldpart.h b/lib/libc/locale/ldpart.h
index 049ab56..becca06 100644
--- a/lib/libc/locale/ldpart.h
+++ b/lib/libc/locale/ldpart.h
@@ -29,6 +29,10 @@
 #ifndef _LDPART_H_
 #define	_LDPART_H_
 
+#define _LDP_LOADED 0
+#define _LDP_ERROR  (-1)
+#define _LDP_CACHE  1
+
 int	__part_load_locale(const char *, int*, char *, const char *,
 		    int, int, const char **);
 
diff --git a/lib/libc/locale/lmessages.c b/lib/libc/locale/lmessages.c
index dd1239e..ed58c99 100644
--- a/lib/libc/locale/lmessages.c
+++ b/lib/libc/locale/lmessages.c
@@ -52,18 +52,19 @@ static char	*_messages_locale_buf;
 int
 __messages_load_locale(const char *name)
 {
-	/*
-	 * Propose that we can have incomplete locale file (w/o "{yes,no}str").
-	 * Initialize them before loading.  In case of complete locale, they'll
-	 * be initialized to loaded value, otherwise they'll not be touched.
-	 */
-	_messages_locale.yesstr = empty;
-	_messages_locale.nostr = empty;
+	int ret;
 
-	return __part_load_locale(name, &_messages_using_locale,
-		_messages_locale_buf, "LC_MESSAGES",
-		LCMESSAGES_SIZE_FULL, LCMESSAGES_SIZE_MIN,
-		(const char **)&_messages_locale);
+	ret = __part_load_locale(name, &_messages_using_locale,
+		  _messages_locale_buf, "LC_MESSAGES",
+		  LCMESSAGES_SIZE_FULL, LCMESSAGES_SIZE_MIN,
+		  (const char **)&_messages_locale);
+	if (ret == _LDP_LOADED) {
+		if (_messages_locale.yesstr == NULL)
+			_messages_locale.yesstr = empty;
+		if (_messages_locale.nostr == NULL)
+			_messages_locale.nostr = empty;
+	}
+	return (ret);
 }
 
 struct lc_messages_T *
diff --git a/lib/libc/locale/lmonetary.c b/lib/libc/locale/lmonetary.c
index eddd1ce..3dc6df0 100644
--- a/lib/libc/locale/lmonetary.c
+++ b/lib/libc/locale/lmonetary.c
@@ -63,7 +63,7 @@ static int	_monetary_using_locale;
 static char	*_monetary_locale_buf;
 
 static char
-cnv(const char *str) 
+cnv(const char *str)
 {
 	int i = strtol(str, NULL, 10);
 
@@ -77,12 +77,13 @@ __monetary_load_locale(const char *name)
 {
 	int ret;
 
-	__mlocale_changed = 1;
 	ret = __part_load_locale(name, &_monetary_using_locale,
 		_monetary_locale_buf, "LC_MONETARY",
 		LCMONETARY_SIZE, LCMONETARY_SIZE,
 		(const char **)&_monetary_locale);
-	if (ret == 0 && _monetary_using_locale) {
+	if (ret != _LDP_ERROR)
+		__mlocale_changed = 1;
+	if (ret == _LDP_LOADED) {
 		_monetary_locale.mon_grouping =
 		     __fix_locale_grouping_str(_monetary_locale.mon_grouping);
 
@@ -102,7 +103,7 @@ __monetary_load_locale(const char *name)
 }
 
 struct lc_monetary_T *
-__get_current_monetary_locale(void) 
+__get_current_monetary_locale(void)
 {
 	return (_monetary_using_locale
 		? &_monetary_locale
diff --git a/lib/libc/locale/lnumeric.c b/lib/libc/locale/lnumeric.c
index 0fb0aab..b1b975e 100644
--- a/lib/libc/locale/lnumeric.c
+++ b/lib/libc/locale/lnumeric.c
@@ -53,14 +53,15 @@ __numeric_load_locale(const char *name)
 {
 	int ret;
 
-	__nlocale_changed = 1;
 	ret = __part_load_locale(name, &_numeric_using_locale,
 		_numeric_locale_buf, "LC_NUMERIC",
 		LCNUMERIC_SIZE, LCNUMERIC_SIZE,
 		(const char **)&_numeric_locale);
-	if (ret == 0 && _numeric_using_locale)
+	if (ret != _LDP_ERROR)
+		__nlocale_changed = 1;
+	if (ret == _LDP_LOADED)
 		_numeric_locale.grouping =
-			__fix_locale_grouping_str(_numeric_locale.grouping);
+		    __fix_locale_grouping_str(_numeric_locale.grouping);
 	return (ret);
 }
 
diff --git a/lib/libc/locale/rune.c b/lib/libc/locale/rune.c
index c67773c..63a50de 100644
--- a/lib/libc/locale/rune.c
+++ b/lib/libc/locale/rune.c
@@ -42,6 +42,7 @@ __FBSDID("$FreeBSD$");
 
 #include "namespace.h"
 #include <arpa/inet.h>
+#include <errno.h>
 #include <rune.h>
 #include <stdio.h>
 #include <string.h>
@@ -59,22 +60,35 @@ _Read_RuneMagi(fp)
 	_RuneLocale *rl;
 	_RuneEntry *rr;
 	struct stat sb;
-	int x;
+	int x, saverr;
 
 	if (_fstat(fileno(fp), &sb) < 0)
-		return(0);
+		return (NULL);
 
-	if (sb.st_size < sizeof(_RuneLocale))
-		return(0);
+	if (sb.st_size < sizeof(_RuneLocale)) {
+		errno = EFTYPE;
+		return (NULL);
+	}
 
-	if ((data = malloc(sb.st_size)) == NULL)
-		return(0);
+	if ((data = malloc(sb.st_size)) == NULL) {
+		errno = ENOMEM;
+		return (NULL);
+	}
 
+	errno = 0;
 	rewind(fp); /* Someone might have read the magic number once already */
+	if (errno) {
+		saverr = errno;
+		free(data);
+		errno = saverr;
+		return (NULL);
+	}
 
 	if (fread(data, sb.st_size, 1, fp) != 1) {
+		saverr = errno;
 		free(data);
-		return(0);
+		errno = saverr;
+		return (NULL);
 	}
 
 	rl = (_RuneLocale *)data;
@@ -84,7 +98,8 @@ _Read_RuneMagi(fp)
 
 	if (memcmp(rl->magic, _RUNE_MAGIC_1, sizeof(rl->magic))) {
 		free(data);
-		return(0);
+		errno = EFTYPE;
+		return (NULL);
 	}
 
 	rl->invalid_rune = ntohl(rl->invalid_rune);
@@ -103,21 +118,24 @@ _Read_RuneMagi(fp)
 	rl->variable = rl->runetype_ext.ranges + rl->runetype_ext.nranges;
 	if (rl->variable > lastp) {
 		free(data);
-		return(0);
+		errno = EFTYPE;
+		return (NULL);
 	}
 
 	rl->maplower_ext.ranges = (_RuneEntry *)rl->variable;
 	rl->variable = rl->maplower_ext.ranges + rl->maplower_ext.nranges;
 	if (rl->variable > lastp) {
 		free(data);
-		return(0);
+		errno = EFTYPE;
+		return (NULL);
 	}
 
 	rl->mapupper_ext.ranges = (_RuneEntry *)rl->variable;
 	rl->variable = rl->mapupper_ext.ranges + rl->mapupper_ext.nranges;
 	if (rl->variable > lastp) {
 		free(data);
-		return(0);
+		errno = EFTYPE;
+		return (NULL);
 	}
 
 	for (x = 0; x < rl->runetype_ext.nranges; ++x) {
@@ -131,7 +149,8 @@ _Read_RuneMagi(fp)
 			rl->variable = rr[x].types + len;
 			if (rl->variable > lastp) {
 				free(data);
-				return(0);
+				errno = EFTYPE;
+				return (NULL);
 			}
 			while (len-- > 0)
 				rr[x].types[len] = ntohl(rr[x].types[len]);
@@ -156,7 +175,8 @@ _Read_RuneMagi(fp)
 	}
 	if (((char *)rl->variable) + rl->variable_len > (char *)lastp) {
 		free(data);
-		return(0);
+		errno = EFTYPE;
+		return (NULL);
 	}
 
 	/*
@@ -174,5 +194,5 @@ _Read_RuneMagi(fp)
 	if (!rl->mapupper_ext.nranges)
 		rl->mapupper_ext.ranges = 0;
 
-	return(rl);
+	return (rl);
 }
diff --git a/lib/libc/locale/setlocale.c b/lib/libc/locale/setlocale.c
index 6b249a9..525ca8f 100644
--- a/lib/libc/locale/setlocale.c
+++ b/lib/libc/locale/setlocale.c
@@ -55,6 +55,7 @@ __FBSDID("$FreeBSD$");
 #include "lnumeric.h"	/* for __numeric_load_locale() */
 #include "lmessages.h"	/* for __messages_load_locale() */
 #include "setlocale.h"
+#include "ldpart.h"
 #include "../stdtime/timelocal.h" /* for __time_load_locale() */
 
 /*
@@ -92,7 +93,7 @@ static char saved_categories[_LC_LAST][ENCODING_LEN + 1];
 static char current_locale_string[_LC_LAST * (ENCODING_LEN + 1/*"/"*/ + 1)];
 
 static char	*currentlocale(void);
-static int      wrap_setrunelocale(char *);
+static int	wrap_setrunelocale(const char *);
 static char	*loadlocale(int);
 
 char *
@@ -206,7 +207,10 @@ setlocale(category, locale)
 			for (j = 1; j < i; j++) {
 				(void)strcpy(new_categories[j],
 					     saved_categories[j]);
-				(void)loadlocale(j);
+				if (loadlocale(j) == NULL) {
+					(void)strcpy(new_categories[j], "C");
+					(void)loadlocale(j);
+				}
 			}
 			errno = saverr;
 			return (NULL);
@@ -235,27 +239,24 @@ currentlocale()
 }
 
 static int
-wrap_setrunelocale(locale)
-	char *locale;
+wrap_setrunelocale(const char *locale)
 {
-	int ret = setrunelocale(locale);
+	int ret = setrunelocale((char *)locale);
 
 	if (ret != 0) {
 		errno = ret;
-		return (-1);
+		return (_LDP_ERROR);
 	}
-	return (0);
+	return (_LDP_LOADED);
 }
 
 static char *
 loadlocale(category)
 	int category;
 {
-	char *ret;
 	char *new = new_categories[category];
 	char *old = current_categories[category];
-	int (*func)();
-	int saverr;
+	int (*func)(const char *);
 
 	if ((new[0] == '.' &&
 	     (new[1] == '\0' || (new[1] == '.' && new[2] == '\0'))) ||
@@ -278,8 +279,10 @@ loadlocale(category)
 				return (NULL);
 			}
 			_PathLocale = strdup(p);
-			if (_PathLocale == NULL)
+			if (_PathLocale == NULL) {
+				errno = ENOMEM;
 				return (NULL);
+			}
 		} else
 			_PathLocale = _PATH_LOCALE;
 	}
@@ -311,15 +314,11 @@ loadlocale(category)
 	if (strcmp(new, old) == 0)
 		return (old);
 
-	ret = func(new) != 0 ? NULL : new;
-	if (ret == NULL) {
-		saverr = errno;
-		if (func(old) != 0 && func("C") == 0)
-			(void)strcpy(old, "C");
-		errno = saverr;
-	} else
+	if (func(new) != _LDP_ERROR) {
 		(void)strcpy(old, new);
+		return (old);
+	}
 
-	return (ret);
+	return (NULL);
 }
 
diff --git a/lib/libc/locale/setrunelocale.c b/lib/libc/locale/setrunelocale.c
index 11d97bd..f1a01fc 100644
--- a/lib/libc/locale/setrunelocale.c
+++ b/lib/libc/locale/setrunelocale.c
@@ -54,12 +54,15 @@ extern int		_MSKanji_init(_RuneLocale *);
 extern _RuneLocale      *_Read_RuneMagi(FILE *);
 
 int
-setrunelocale(encoding)
-	char *encoding;
+setrunelocale(char *encoding)
 {
 	FILE *fp;
 	char name[PATH_MAX];
 	_RuneLocale *rl;
+	int saverr, ret;
+	static char ctype_encoding[ENCODING_LEN + 1];
+	static _RuneLocale *CachedRuneLocale;
+	static int Cached__mb_cur_max;
 
 	if (!encoding || !*encoding || strlen(encoding) > ENCODING_LEN ||
 	    (encoding[0] == '.' &&
@@ -71,12 +74,25 @@ setrunelocale(encoding)
 	/*
 	 * The "C" and "POSIX" locale are always here.
 	 */
-	if (!strcmp(encoding, "C") || !strcmp(encoding, "POSIX")) {
+	if (strcmp(encoding, "C") == 0 || strcmp(encoding, "POSIX") == 0) {
 		_CurrentRuneLocale = &_DefaultRuneLocale;
 		__mb_cur_max = 1;
 		return (0);
 	}
 
+	/*
+	 * If the locale name is the same as our cache, use the cache.
+	 */
+	if (CachedRuneLocale != NULL &&
+	    strcmp(encoding, ctype_encoding) == 0) {
+		_CurrentRuneLocale = CachedRuneLocale;
+		__mb_cur_max = Cached__mb_cur_max;
+		return (0);
+	}
+
+	/*
+	 * Slurp the locale file into the cache.
+	 */
 	if (_PathLocale == NULL) {
 		char *p = getenv("PATH_LOCALE");
 
@@ -90,7 +106,7 @@ setrunelocale(encoding)
 				return (ENAMETOOLONG);
 			_PathLocale = strdup(p);
 			if (_PathLocale == NULL)
-				return (errno);
+				return (ENOMEM);
 		} else
 			_PathLocale = _PATH_LOCALE;
 	}
@@ -103,25 +119,38 @@ setrunelocale(encoding)
 	if ((fp = fopen(name, "r")) == NULL)
 		return (errno);
 
-	if ((rl = _Read_RuneMagi(fp)) == 0) {
-		fclose(fp);
-		return (EFTYPE);
+	if ((rl = _Read_RuneMagi(fp)) == NULL) {
+		saverr = errno;
+		(void)fclose(fp);
+		return (saverr);
 	}
-	fclose(fp);
+	(void)fclose(fp);
 
-	if (!rl->encoding[0])
-		return (EFTYPE);
-	else if (!strcmp(rl->encoding, "NONE"))
-		return (_none_init(rl));
-	else if (!strcmp(rl->encoding, "UTF2"))
-		return (_UTF2_init(rl));
-	else if (!strcmp(rl->encoding, "EUC"))
-		return (_EUC_init(rl));
-	else if (!strcmp(rl->encoding, "BIG5"))
-		return (_BIG5_init(rl));
-	else if (!strcmp(rl->encoding, "MSKanji"))
-		return (_MSKanji_init(rl));
+	if (strcmp(rl->encoding, "NONE") == 0)
+		ret = _none_init(rl);
+	else if (strcmp(rl->encoding, "UTF2") == 0)
+		ret = _UTF2_init(rl);
+	else if (strcmp(rl->encoding, "EUC") == 0)
+		ret = _EUC_init(rl);
+	else if (strcmp(rl->encoding, "BIG5") == 0)
+		ret = _BIG5_init(rl);
+	else if (strcmp(rl->encoding, "MSKanji") == 0)
+		ret = _MSKanji_init(rl);
 	else
-		return (EFTYPE);
+		ret = EFTYPE;
+	if (ret == 0) {
+		if (CachedRuneLocale != NULL) {
+			/* See euc.c */
+			if (strcmp(CachedRuneLocale->encoding, "EUC") == 0)
+				free(CachedRuneLocale->variable);
+			free(CachedRuneLocale);
+		}
+		CachedRuneLocale = _CurrentRuneLocale;
+		Cached__mb_cur_max = __mb_cur_max;
+		(void)strcpy(ctype_encoding, encoding);
+	} else
+		free(rl);
+
+	return (ret);
 }