Back-patch addition of pg_wchar-to-multibyte conversion functionality.

Back-patch of commits 72dd6291f216440f6bb61a8733729a37c7e3b2d2,
f6a05fd973a102f7e66c491d3f854864b8d24844, and
60e9c224a197aa37abb1aa3aefa3aad42da61f7f.

This is needed to support fixing the regex prefix extraction bug in
back branches.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c
index 9a739019531..6f798154583 100644
--- a/src/backend/utils/mb/mbutils.c
+++ b/src/backend/utils/mb/mbutils.c
@@ -751,6 +751,28 @@ pg_encoding_mb2wchar_with_len(int encoding,
 	return (*pg_wchar_table[encoding].mb2wchar_with_len) ((const unsigned char *) from, to, len);
 }
 
+/* convert a wchar string to a multibyte */
+int
+pg_wchar2mb(const pg_wchar *from, char *to)
+{
+	return (*pg_wchar_table[DatabaseEncoding->encoding].wchar2mb_with_len) (from, (unsigned char *)to, pg_wchar_strlen(from));
+}
+
+/* convert a wchar string to a multibyte with a limited length */
+int
+pg_wchar2mb_with_len(const pg_wchar *from, char *to, int len)
+{
+	return (*pg_wchar_table[DatabaseEncoding->encoding].wchar2mb_with_len) (from, (unsigned char *)to, len);
+}
+
+/* same, with any encoding */
+int
+pg_encoding_wchar2mb_with_len(int encoding,
+							  const pg_wchar *from, char *to, int len)
+{
+	return (*pg_wchar_table[encoding].wchar2mb_with_len) (from, (unsigned char *)to, len);
+}
+
 /* returns the byte length of a multibyte character */
 int
 pg_mblen(const char *mbstr)