Catch invalid typlens in a couple of places

Rearrange the logic in record_image_cmp() and datum_image_eq() to
error out on unexpected typlens (either not supported there or
completely invalid due to corruption).  Barring corruption, this is
not possible today but it seems more future-proof and robust to fix
this.

Reported-by: Peter Geoghegan <pg@bowt.ie>
This commit is contained in:
Peter Eisentraut 2019-11-04 08:30:00 +01:00
parent db27b60f07
commit 8557a6f10c
2 changed files with 25 additions and 21 deletions

View File

@ -265,7 +265,17 @@ datum_image_eq(Datum value1, Datum value2, bool typByVal, int typLen)
{
bool result = true;
if (typLen == -1)
if (typByVal)
{
result = (value1 == value2);
}
else if (typLen > 0)
{
result = (memcmp(DatumGetPointer(value1),
DatumGetPointer(value2),
typLen) == 0);
}
else if (typLen == -1)
{
Size len1,
len2;
@ -294,16 +304,8 @@ datum_image_eq(Datum value1, Datum value2, bool typByVal, int typLen)
pfree(arg2val);
}
}
else if (typByVal)
{
result = (value1 == value2);
}
else
{
result = (memcmp(DatumGetPointer(value1),
DatumGetPointer(value2),
typLen) == 0);
}
elog(ERROR, "unexpected typLen: %d", typLen);
return result;
}

View File

@ -1443,7 +1443,18 @@ record_image_cmp(FunctionCallInfo fcinfo)
}
/* Compare the pair of elements */
if (att1->attlen == -1)
if (att1->attbyval)
{
if (values1[i1] != values2[i2])
cmpresult = (values1[i1] < values2[i2]) ? -1 : 1;
}
else if (att1->attlen > 0)
{
cmpresult = memcmp(DatumGetPointer(values1[i1]),
DatumGetPointer(values2[i2]),
att1->attlen);
}
else if (att1->attlen == -1)
{
Size len1,
len2;
@ -1466,17 +1477,8 @@ record_image_cmp(FunctionCallInfo fcinfo)
if ((Pointer) arg2val != (Pointer) values2[i2])
pfree(arg2val);
}
else if (att1->attbyval)
{
if (values1[i1] != values2[i2])
cmpresult = (values1[i1] < values2[i2]) ? -1 : 1;
}
else
{
cmpresult = memcmp(DatumGetPointer(values1[i1]),
DatumGetPointer(values2[i2]),
att1->attlen);
}
elog(ERROR, "unexpected attlen: %d", att1->attlen);
if (cmpresult < 0)
{