diff options
| author | Tom Lane <tgl@sss.pgh.pa.us> | 2010-01-07 19:53:16 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2010-01-07 19:53:16 +0000 |
| commit | ac7fc991c0234cc7594187a5206b566fe1deff20 (patch) | |
| tree | f30dfa3918130b368343e76384dad48429476f8e | |
| parent | ed62e74522568a2099ca8f7152fc7e36d6702cbb (diff) | |
| download | postgresql-ac7fc991c0234cc7594187a5206b566fe1deff20.tar.gz postgresql-ac7fc991c0234cc7594187a5206b566fe1deff20.zip | |
Make bit/varbit substring() treat any negative length as meaning "all the rest
of the string". The previous coding treated only -1 that way, and would
produce an invalid result value for other negative values.
We ought to fix it so that 2-parameter bit substring() is a different C
function and the 3-parameter form throws error for negative length, but
that takes a pg_proc change which is impractical in the back branches;
and in any case somebody might be relying on -1 working this way.
So just do this as a back-patchable fix.
| -rw-r--r-- | src/backend/utils/adt/varbit.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/src/backend/utils/adt/varbit.c b/src/backend/utils/adt/varbit.c index 35a79a0b147..aebc2baf1f5 100644 --- a/src/backend/utils/adt/varbit.c +++ b/src/backend/utils/adt/varbit.c @@ -9,7 +9,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/varbit.c,v 1.58.2.1 2009/12/12 19:24:44 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/varbit.c,v 1.58.2.2 2010/01/07 19:53:16 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -945,13 +945,23 @@ bitsubstr(PG_FUNCTION_ARGS) *ps; bitlen = VARBITLEN(arg); - /* If we do not have an upper bound, set bitlen */ - if (l == -1) - l = bitlen; - e = s + l; s1 = Max(s, 1); - e1 = Min(e, bitlen + 1); - if (s1 > bitlen || e1 < 1) + /* If we do not have an upper bound, use end of string */ + if (l < 0) + { + e1 = bitlen + 1; + } + else + { + e = s + l; + /* guard against overflow, even though we don't allow L<0 here */ + if (e < s) + ereport(ERROR, + (errcode(ERRCODE_SUBSTRING_ERROR), + errmsg("negative substring length not allowed"))); + e1 = Min(e, bitlen + 1); + } + if (s1 > bitlen || e1 <= s1) { /* Need to return a zero-length bitstring */ len = VARBITTOTALLEN(0); |