pg_locale_libc.c: add guards to ctype methods.

Necessary for 16-bit wchar_t platforms (Windows).

Other guards are just defensive. Also correct style issue with
branches.

Reported-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/20260630012919.78@rfd.leadboat.com
Backpatch-through: 19

diff --git a/src/backend/utils/adt/pg_locale_libc.c b/src/backend/utils/adt/pg_locale_libc.c
index 37e26b7e7a872e470a539abb3455c6ade4e93696..0043371586dc73af525ede7520ae21150565949f 100644 (file)
--- a/src/backend/utils/adt/pg_locale_libc.c
+++ b/src/backend/utils/adt/pg_locale_libc.c
@@ -124,60 +124,80 @@ static size_t strupper_libc_mb(char *dest, size_t destsize,
 static bool
 wc_isdigit_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return isdigit_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_isalpha_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return isalpha_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_isalnum_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return isalnum_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_isupper_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return isupper_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_islower_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return islower_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_isgraph_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return isgraph_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_isprint_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return isprint_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_ispunct_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return ispunct_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_isspace_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return isspace_l((unsigned char) wc, locale->lt);
 }
 
 static bool
 wc_isxdigit_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
 #ifndef WIN32
        return isxdigit_l((unsigned char) wc, locale->lt);
 #else
@@ -188,6 +208,8 @@ wc_isxdigit_libc_sb(pg_wchar wc, pg_locale_t locale)
 static bool
 wc_iscased_libc_sb(pg_wchar wc, pg_locale_t locale)
 {
+       if (wc > UCHAR_MAX)
+               return false;
        return isupper_l((unsigned char) wc, locale->lt) ||
                islower_l((unsigned char) wc, locale->lt);
 }
@@ -195,60 +217,80 @@ wc_iscased_libc_sb(pg_wchar wc, pg_locale_t locale)
 static bool
 wc_isdigit_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswdigit_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_isalpha_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswalpha_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_isalnum_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswalnum_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_isupper_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswupper_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_islower_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswlower_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_isgraph_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswgraph_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_isprint_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswprint_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_ispunct_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswpunct_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_isspace_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswspace_l((wint_t) wc, locale->lt);
 }
 
 static bool
 wc_isxdigit_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
 #ifndef WIN32
        return iswxdigit_l((wint_t) wc, locale->lt);
 #else
@@ -259,6 +301,8 @@ wc_isxdigit_libc_mb(pg_wchar wc, pg_locale_t locale)
 static bool
 wc_iscased_libc_mb(pg_wchar wc, pg_locale_t locale)
 {
+       if (sizeof(wchar_t) < 4 && wc > (pg_wchar) 0xFFFF)
+               return false;
        return iswupper_l((wint_t) wc, locale->lt) ||
                iswlower_l((wint_t) wc, locale->lt);
 }
@@ -271,7 +315,7 @@ toupper_libc_sb(pg_wchar wc, pg_locale_t locale)
        /* force C behavior for ASCII characters, per comments above */
        if (locale->is_default && wc <= (pg_wchar) 127)
                return pg_ascii_toupper((unsigned char) wc);
-       if (wc <= (pg_wchar) UCHAR_MAX)
+       else if (wc <= (pg_wchar) UCHAR_MAX)
                return toupper_l((unsigned char) wc, locale->lt);
        else
                return wc;
@@ -285,7 +329,7 @@ toupper_libc_mb(pg_wchar wc, pg_locale_t locale)
        /* force C behavior for ASCII characters, per comments above */
        if (locale->is_default && wc <= (pg_wchar) 127)
                return pg_ascii_toupper((unsigned char) wc);
-       if (sizeof(wchar_t) >= 4 || wc <= (pg_wchar) 0xFFFF)
+       else if (sizeof(wchar_t) >= 4 || wc <= (pg_wchar) 0xFFFF)
                return towupper_l((wint_t) wc, locale->lt);
        else
                return wc;
@@ -299,7 +343,7 @@ tolower_libc_sb(pg_wchar wc, pg_locale_t locale)
        /* force C behavior for ASCII characters, per comments above */
        if (locale->is_default && wc <= (pg_wchar) 127)
                return pg_ascii_tolower((unsigned char) wc);
-       if (wc <= (pg_wchar) UCHAR_MAX)
+       else if (wc <= (pg_wchar) UCHAR_MAX)
                return tolower_l((unsigned char) wc, locale->lt);
        else
                return wc;
@@ -313,7 +357,7 @@ tolower_libc_mb(pg_wchar wc, pg_locale_t locale)
        /* force C behavior for ASCII characters, per comments above */
        if (locale->is_default && wc <= (pg_wchar) 127)
                return pg_ascii_tolower((unsigned char) wc);
-       if (sizeof(wchar_t) >= 4 || wc <= (pg_wchar) 0xFFFF)
+       else if (sizeof(wchar_t) >= 4 || wc <= (pg_wchar) 0xFFFF)
                return towlower_l((wint_t) wc, locale->lt);
        else
                return wc;