Blender Git Loki

Cleanup: Strict compiler flags

Mainly caused by moving tests to source folder, which brings
new compiler flags.

Also, no need to extend include directories (to the non-existing paths,
btw) since this is done by the CmakeList.txt which is in the blenlib folder.

Depsgraph: Use UUID to match modifiers

Solves possible pointer-based comparison fiasco.

Another nice outcome of this is that topology cache will now be
preserved throughout the undo system. For example, undo of object
transform will not require topology cache to be re-created.

Differential Revision: https://developer.blender.org/D8493

Modifier: Maintain per-modifier session UUID

Allows to keep track of modifiers, which is required, for example,
for runtime data preservation in depsgraph.

Fix path regression test build failure on Windows

The file was including BKE. It was a required fix for another
compilation error a while back. It is a bad level include, and
seems is not needed anymore.

Merge branch 'blender-v2.90-release' into master

Fix memory leak setting error text in the data-transfer modifier

Merge branch 'blender-v2.90-release' into master

Merge branch 'blender-v2.90-release' into master

Merge branch 'blender-v2.90-release' into master

Fix T77409: Crash showing vertex/face duplicators in edit-mode

Support duplicators in edit-mode without creating a mesh copy.

BMesh: add UV calculate center call

Move uv_poly_center to BM_face_uv_calc_center_median as
it was only defined in uvedit_intern.h

Cleanup: use doxy sections for object_dupli.c

Cleanup: GCC warning in guardedalloc_overflow_test

Cleanup: spelling

Merge branch 'blender-v2.90-release'

Fix T77298: Can't bake texture with multiple objects

The problem here is that the baking code uses tiles to exchange pixel data with
the renderer since a recent-ish refactor, but the code that sent data to the
renderer did not initialize the bake result pixels.

Therefore, when the baking process for the second object started, Cycles
received empty tiles and sent them back as-is if the second object did not
cover them.

By initializing the tiles with the result of the previous bakes, we avoid this
problem.

Merge branch 'blender-v2.90-release'

Fix T79636: Inserting special characters with Ctrl+Alt broken on Windows

We can't exactly follow what we do for macOS here. On Windows special
characters can be inserted with Ctrl+Alt. So make sure we expect UTF-8
characters when Alt is held.

Mistake in 87062d4d670c.

Cleanup: follow code style regarding braces

BLI: improve StringRef for C++17

Since C++17 there is also std::string_view, which is similar to StringRef.
This commit does a couple of things:
* New implicit conversions between StringRef and std::string_view.
* Support std::string_view in blender::DefaultHash.
* Support most of the methods that std::string_view has.
* Add StringRef::not_found which can be used instead of -1 in some places.
* Improve/fix the description at the top of BLI_string_ref.hh.