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Fix bogus calculation of potential output string length in translate().

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This commit is contained in:
Tom Lane 2007-09-22 05:35:52 +00:00
parent d5e6f4f828
commit a9f08b41ac
1 changed files with 20 additions and 13 deletions
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33
src/backend/utils/adt/oracle_compat.c
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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/oracle_compat.c,v 1.67.2.1 2007/02/08 20:33:54 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/oracle_compat.c,v 1.67.2.2 2007/09/22 05:35:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -1153,27 +1153,34 @@ translate(PG_FUNCTION_ARGS)
tolen,
retlen,
i;
int str_len;
int estimate_len;
int worst_len;
int len;
int source_len;
int from_index;
if ((m = VARSIZE(string) - VARHDRSZ) <= 0)
m = VARSIZE(string) - VARHDRSZ;
if (m <= 0)
PG_RETURN_TEXT_P(string);
source = VARDATA(string);
fromlen = VARSIZE(from) - VARHDRSZ;
from_ptr = VARDATA(from);
tolen = VARSIZE(to) - VARHDRSZ;
to_ptr = VARDATA(to);
str_len = VARSIZE(string);
estimate_len = (tolen * 1.0 / fromlen + 0.5) * str_len;
estimate_len = estimate_len > str_len ? estimate_len : str_len;
result = (text *) palloc(estimate_len);
/*
* The worst-case expansion is to substitute a max-length character for
* a single-byte character at each position of the string.
*/
worst_len = pg_database_encoding_max_length() * m;
source = VARDATA(string);
/* check for integer overflow */
if (worst_len / pg_database_encoding_max_length() != m)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("requested length too large")));
result = (text *) palloc(worst_len + VARHDRSZ);
target = VARDATA(result);
retlen = 0;
@ -1226,9 +1233,9 @@ translate(PG_FUNCTION_ARGS)
VARATT_SIZEP(result) = retlen + VARHDRSZ;
/*
* There may be some wasted space in the result if deletions occurred, but
* it's not worth reallocating it; the function result probably won't live
* long anyway.
* The function result is probably much bigger than needed, if we're
* using a multibyte encoding, but it's not worth reallocating it;
* the result probably won't live long anyway.
*/
PG_RETURN_TEXT_P(result);