Don't downcase non-ascii identifier chars in multi-byte encodings.

Long-standing code has called tolower() on identifier character bytes
with the high bit set. This is clearly an error and produces junk output
when the encoding is multi-byte. This patch therefore restricts this
activity to cases where there is a character with the high bit set AND
the encoding is single-byte.

There have been numerous gripes about this, most recently from Martin
Schäfer.

Backpatch to all live releases.
This commit is contained in:
Andrew Dunstan 2013-06-08 10:00:09 -04:00
parent 94e3311b97
commit d535136b5d
1 changed files with 5 additions and 3 deletions

View File

@ -132,8 +132,10 @@ downcase_truncate_identifier(const char *ident, int len, bool warn)
{
char *result;
int i;
bool enc_is_single_byte;
result = palloc(len + 1);
enc_is_single_byte = pg_database_encoding_max_length() == 1;
/*
* SQL99 specifies Unicode-aware case normalization, which we don't yet
@ -141,8 +143,8 @@ downcase_truncate_identifier(const char *ident, int len, bool warn)
* locale-aware translation. However, there are some locales where this
* is not right either (eg, Turkish may do strange things with 'i' and
* 'I'). Our current compromise is to use tolower() for characters with
* the high bit set, and use an ASCII-only downcasing for 7-bit
* characters.
* the high bit set, as long as they aren't part of a multi-byte character,
* and use an ASCII-only downcasing for 7-bit characters.
*/
for (i = 0; i < len; i++)
{
@ -150,7 +152,7 @@ downcase_truncate_identifier(const char *ident, int len, bool warn)
if (ch >= 'A' && ch <= 'Z')
ch += 'a' - 'A';
else if (IS_HIGHBIT_SET(ch) && isupper(ch))
else if (enc_is_single_byte && IS_HIGHBIT_SET(ch) && isupper(ch))
ch = tolower(ch);
result[i] = (char) ch;
}