Apparent bug in OGRFieldDefn assignment operator

[bugpower]

I haven't researched it deeply, but here's how it looks.

This code works:

static void CreateStandardPolygonFields(OGRLayer *poLayer)
{
	OGRFieldDefn field1("Name", OGRFieldType::OFTString);
	field1.SetWidth(32);
	poLayer->CreateField(&field1);

	OGRFieldDefn field2("Session", OGRFieldType::OFTString);
	field2.SetWidth(128);
	poLayer->CreateField(&field2);

	OGRFieldDefn field3("Time", OGRFieldType::OFTString);
	field3.SetWidth(32);
	poLayer->CreateField(&field3);

	OGRFieldDefn field5("Position stream", OGRFieldType::OFTString);
	field5.SetWidth(32);
	poLayer->CreateField(&field5);

	OGRFieldDefn field6("Area_km2", OGRFieldType::OFTReal);
	poLayer->CreateField(&field6);
}

This one causes heap corruption on return:

static void CreateStandardPolygonFields(OGRLayer *poLayer)
{
	OGRFieldDefn field("Name", OGRFieldType::OFTString);
	field.SetWidth(32);
	poLayer->CreateField(&field);

	field = OGRFieldDefn("Session", OGRFieldType::OFTString);
	field.SetWidth(32);
	poLayer->CreateField(&field);

	field = OGRFieldDefn("Time", OGRFieldType::OFTString);
	field.SetWidth(32);
	poLayer->CreateField(&field);

	field = OGRFieldDefn("Position stream", OGRFieldType::OFTString);
	field.SetWidth(32);
	poLayer->CreateField(&field);

	field = OGRFieldDefn("Area_km2", OGRFieldType::OFTReal);
	poLayer->CreateField(&field);
}

The only difference is recycling the same "field" which should be okay.

[warmerdam]

I've never seen something like:

  OGRFieldDefn field(...);

  field = OGRFieldDefn("Area_km2", OGRFieldType::OFTReal); 

before and I can't understand how it is intended to work.

[warmerdam]

I don't see an action item so I'm closing. Please reopen if you see something that needs to be done.

[bugpower]

Explaining.

(if compiles) it is expected to overwrite the existing local with a temporary. From there it should be equivalent. It is not, this is the symptom.

[Even Rouault]

r26461 "Add copy constructor and assigment operator to OGRFieldDefn (#5043)"

[Even Rouault]

r26462 "Revert r26461 since it causes crashes on Windows, because the default assigment operator that does bit-to-bit copy is used instead of our specialized version, for some unknown reason... (#5043)"

[Even Rouault]

Dealt by #6100 (explicitly disabling copy constructor and assigment operator)