From bbda96d76d6a10bbd662e4e71135b188e23a815b Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 22 Sep 2007 05:35:42 +0000 Subject: [PATCH] Fix bogus calculation of potential output string length in translate(). --- src/backend/utils/adt/oracle_compat.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/src/backend/utils/adt/oracle_compat.c b/src/backend/utils/adt/oracle_compat.c index db8c25aa67..56fe7a607f 100644 --- a/src/backend/utils/adt/oracle_compat.c +++ b/src/backend/utils/adt/oracle_compat.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/oracle_compat.c,v 1.72 2007/09/21 22:52:52 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/oracle_compat.c,v 1.73 2007/09/22 05:35:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1162,30 +1162,34 @@ translate(PG_FUNCTION_ARGS) tolen, retlen, i; - - int str_len; - int estimate_len; + int worst_len; int len; int source_len; int from_index; m = VARSIZE_ANY_EXHDR(string); - if (m <= 0) PG_RETURN_TEXT_P(string); + source = VARDATA_ANY(string); fromlen = VARSIZE_ANY_EXHDR(from); from_ptr = VARDATA_ANY(from); tolen = VARSIZE_ANY_EXHDR(to); to_ptr = VARDATA_ANY(to); - str_len = VARSIZE_ANY_EXHDR(string); - source = VARDATA_ANY(string); + /* + * 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; - estimate_len = (tolen * 1.0 / fromlen + 0.5) * str_len; - estimate_len = estimate_len > str_len ? estimate_len : str_len; + /* 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(estimate_len + VARHDRSZ); + result = (text *) palloc(worst_len + VARHDRSZ); target = VARDATA(result); retlen = 0; @@ -1238,9 +1242,9 @@ translate(PG_FUNCTION_ARGS) SET_VARSIZE(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); -- 2.11.0