diff options
Diffstat (limited to 'src/backend/parser/parse_coerce.c')
| -rw-r--r-- | src/backend/parser/parse_coerce.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/src/backend/parser/parse_coerce.c b/src/backend/parser/parse_coerce.c index f6e7be4e710..589183c277e 100644 --- a/src/backend/parser/parse_coerce.c +++ b/src/backend/parser/parse_coerce.c @@ -26,6 +26,7 @@ #include "parser/parse_relation.h" #include "parser/parse_type.h" #include "utils/builtins.h" +#include "utils/datum.h" #include "utils/lsyscache.h" #include "utils/syscache.h" #include "utils/typcache.h" @@ -308,6 +309,43 @@ coerce_type(ParseState *pstate, Node *node, NULL, inputTypeMod); + /* + * If it's a varlena value, force it to be in non-expanded + * (non-toasted) format; this avoids any possible dependency on + * external values and improves consistency of representation. + */ + if (!con->constisnull && newcon->constlen == -1) + newcon->constvalue = + PointerGetDatum(PG_DETOAST_DATUM(newcon->constvalue)); + +#ifdef RANDOMIZE_ALLOCATED_MEMORY + + /* + * For pass-by-reference data types, repeat the conversion to see if + * the input function leaves any uninitialized bytes in the result. We + * can only detect that reliably if RANDOMIZE_ALLOCATED_MEMORY is + * enabled, so we don't bother testing otherwise. The reason we don't + * want any instability in the input function is that comparison of + * Const nodes relies on bytewise comparison of the datums, so if the + * input function leaves garbage then subexpressions that should be + * identical may not get recognized as such. See pgsql-hackers + * discussion of 2008-04-04. + */ + if (!con->constisnull && !newcon->constbyval) + { + Datum val2; + + val2 = stringTypeDatum(baseType, + DatumGetCString(con->constvalue), + inputTypeMod); + if (newcon->constlen == -1) + val2 = PointerGetDatum(PG_DETOAST_DATUM(val2)); + if (!datumIsEqual(newcon->constvalue, val2, false, newcon->constlen)) + elog(WARNING, "type %s has unstable input conversion for \"%s\"", + typeTypeName(baseType), DatumGetCString(con->constvalue)); + } +#endif + cancel_parser_errposition_callback(&pcbstate); result = (Node *) newcon; |