From 81f91de9f776f91e2eee6815d452c520f892ced3 Mon Sep 17 00:00:00 2001
From: Eric van Gyzen <vangyzen@FreeBSD.org>
Date: Sun, 20 Nov 2016 20:13:22 +0000
Subject: [PATCH] Fix error reporting from wcstof()

When wcstof() skipped initial space and then parsing failed, it set
endptr to the first non-space character.  Fix it to correctly report
failure by setting endptr to the beginning of the input string.
The fix is from theraven@, who fixed this bug in wcstod() and
wcstold() in r227753.

While I'm here:

Move assignments out of declarations in wcstod() and wcstold().
This is against my personal preference, but it is our agreed style(9).

Set endptr correctly on malloc() failure in all three functions.

Remove an incorrect comment:  This is pointer arithmetic,
so the code was not actually making that assumption.

wcstold() advanced the wcp pointer beyond leading whitespace
and then reset it back to the beginning of the string.
Do not reset it.  This seems to have no functional effect,
since strtold_l() also skips leading whitespace.  I'm making
the change to keep this function consistent with wcstof() and
wcstod(), and because the C11 spec prescribes the use of iswspace()
to skip leading space.

Reported by:	libc++ unit test for std::stof(std::wstring)
MFC after:	8 days
Sponsored by:	Dell EMC
---
 lib/libc/locale/wcstod.c  | 13 ++++++++-----
 lib/libc/locale/wcstof.c  | 20 +++++++++++++++-----
 lib/libc/locale/wcstold.c | 13 ++++++++-----
 3 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/lib/libc/locale/wcstod.c b/lib/libc/locale/wcstod.c
index 8bc46a7c3ad..c6ae1417c1d 100644
--- a/lib/libc/locale/wcstod.c
+++ b/lib/libc/locale/wcstod.c
@@ -54,11 +54,13 @@ wcstod_l(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr,
 	mbstate_t mbs;
 	double val;
 	char *buf, *end;
-	const wchar_t *wcp = nptr;
+	const wchar_t *wcp;
 	size_t len;
-	size_t spaces = 0;
+	size_t spaces;
 	FIX_LOCALE(locale);
 
+	wcp = nptr;
+	spaces = 0;
 	while (iswspace_l(*wcp, locale)) {
 		wcp++;
 		spaces++;
@@ -80,8 +82,11 @@ wcstod_l(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr,
 			*endptr = (wchar_t *)nptr;
 		return (0.0);
 	}
-	if ((buf = malloc(len + 1)) == NULL)
+	if ((buf = malloc(len + 1)) == NULL) {
+		if (endptr != NULL)
+			*endptr = (wchar_t *)nptr;
 		return (0.0);
+	}
 	mbs = initial;
 	wcsrtombs_l(buf, &wcp, len + 1, &mbs, locale);
 
@@ -95,13 +100,11 @@ wcstod_l(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr,
 	 * corresponding position in the wide char string.
 	 */
 	if (endptr != NULL) {
-		/* XXX Assume each wide char is one byte. */
 		*endptr = (wchar_t *)nptr + (end - buf);
 		if (buf != end)
 			*endptr += spaces;
 	}
 
-
 	free(buf);
 
 	return (val);
diff --git a/lib/libc/locale/wcstof.c b/lib/libc/locale/wcstof.c
index 93a5af83818..99ce0fe4af2 100644
--- a/lib/libc/locale/wcstof.c
+++ b/lib/libc/locale/wcstof.c
@@ -50,27 +50,37 @@ wcstof_l(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr,
 	char *buf, *end;
 	const wchar_t *wcp;
 	size_t len;
+	size_t spaces;
 	FIX_LOCALE(locale);
 
-	while (iswspace_l(*nptr, locale))
-		nptr++;
-
 	wcp = nptr;
+	spaces = 0;
+	while (iswspace_l(*wcp, locale)) {
+		wcp++;
+		spaces++;
+	}
+
 	mbs = initial;
 	if ((len = wcsrtombs_l(NULL, &wcp, 0, &mbs, locale)) == (size_t)-1) {
 		if (endptr != NULL)
 			*endptr = (wchar_t *)nptr;
 		return (0.0);
 	}
-	if ((buf = malloc(len + 1)) == NULL)
+	if ((buf = malloc(len + 1)) == NULL) {
+		if (endptr != NULL)
+			*endptr = (wchar_t *)nptr;
 		return (0.0);
+	}
 	mbs = initial;
 	wcsrtombs_l(buf, &wcp, len + 1, &mbs, locale);
 
 	val = strtof_l(buf, &end, locale);
 
-	if (endptr != NULL)
+	if (endptr != NULL) {
 		*endptr = (wchar_t *)nptr + (end - buf);
+		if (buf != end)
+			*endptr += spaces;
+	}
 
 	free(buf);
 
diff --git a/lib/libc/locale/wcstold.c b/lib/libc/locale/wcstold.c
index fcfd48f12d0..89c92d95d4f 100644
--- a/lib/libc/locale/wcstold.c
+++ b/lib/libc/locale/wcstold.c
@@ -48,32 +48,35 @@ wcstold_l(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr,
 	mbstate_t mbs;
 	long double val;
 	char *buf, *end;
-	const wchar_t *wcp = nptr;
+	const wchar_t *wcp;
 	size_t len;
-	size_t spaces = 0;
+	size_t spaces;
 	FIX_LOCALE(locale);
 
+	wcp = nptr;
+	spaces = 0;
 	while (iswspace_l(*wcp, locale)) {
 		wcp++;
 		spaces++;
 	}
 
-	wcp = nptr;
 	mbs = initial;
 	if ((len = wcsrtombs_l(NULL, &wcp, 0, &mbs, locale)) == (size_t)-1) {
 		if (endptr != NULL)
 			*endptr = (wchar_t *)nptr;
 		return (0.0);
 	}
-	if ((buf = malloc(len + 1)) == NULL)
+	if ((buf = malloc(len + 1)) == NULL) {
+		if (endptr != NULL)
+			*endptr = (wchar_t *)nptr;
 		return (0.0);
+	}
 	mbs = initial;
 	wcsrtombs_l(buf, &wcp, len + 1, &mbs, locale);
 
 	val = strtold_l(buf, &end, locale);
 
 	if (endptr != NULL) {
-		/* XXX Assume each wide char is one byte. */
 		*endptr = (wchar_t *)nptr + (end - buf);
 		if (buf != end)
 			*endptr += spaces;