diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/access/common/tupdesc.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c index fb5c199c0c4..b823d978b0c 100644 --- a/src/backend/access/common/tupdesc.c +++ b/src/backend/access/common/tupdesc.c @@ -434,6 +434,12 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2) * This function initializes a single attribute structure in * a previously allocated tuple descriptor. * + * If attributeName is NULL, the attname field is set to an empty string + * (this is for cases where we don't know or need a name for the field). + * Also, some callers use this function to change the datatype-related fields + * in an existing tupdesc; they pass attributeName = NameStr(att->attname) + * to indicate that the attname field shouldn't be modified. + * * Note that attcollation is set to the default for the specified datatype. * If a nondefault collation is needed, insert it afterwards using * TupleDescInitEntryCollation. @@ -467,12 +473,12 @@ TupleDescInitEntry(TupleDesc desc, /* * Note: attributeName can be NULL, because the planner doesn't always * fill in valid resname values in targetlists, particularly for resjunk - * attributes. + * attributes. Also, do nothing if caller wants to re-use the old attname. */ - if (attributeName != NULL) - namestrcpy(&(att->attname), attributeName); - else + if (attributeName == NULL) MemSet(NameStr(att->attname), 0, NAMEDATALEN); + else if (attributeName != NameStr(att->attname)) + namestrcpy(&(att->attname), attributeName); att->attstattarget = -1; att->attcacheoff = -1; |