After 1d961491d8, palettes are different
if they either have different brush data, or a different private. Two
privates can share data, but still must generate different cache keys.
The cacheKey has so far been composted of the serial number of the Data
struct, and a detach number that is incremented when we detach the
private.
This failed for two reasons:
- the implicit copy constructor of the Data class copied the serial
number, when it should have incremented it. Fix that by member-
initializing the serial number rather than doing it only in the default
constructor. The member initialization is also executed for the copy
constructor.
- the detach_no logic as it was implemented does not guarantee that two
copies of the same palette that share data, but have different resolve
masks (and thus different privates) have different detach_no values.
Use a static serial counter for that number as well.
Amend the test case to verfiy that cache keys, and the elements of the
cache keys, change when they are expected to.
Fixes: QTBUG-106984
Pick-to: 6.2 6.4
Change-Id: I84d7055ce8bfe0d42f1f8e9766f3f1ad610f4ec8
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
109e088c7c