[qt/qt/qtbase]: Summary of bulk changes made

Git repository change summary for qt/qt/qtbase
Pushed by mirror-service into branch '6.12'.
Changed from 499bffa4b9f6dc92dccfc5c3092c4ef6ddb1536d to 617242bba272518b57f7c201d63af299abcb877b
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit a6146bc05354345a31d600be1085d536781516e3 by Qt Cherry-pick Bot (on behalf of Han Xueyan) on 30/07/2026 at 05:34..
QToolButton: avoid duplicate default action connections

Handling ActionChanged calls setDefaultAction() again with the existing
action. This repeatedly connects QAction::changed to the same private
slot, causing the connection list and signal delivery cost to grow with
each action update.

Use a unique connection and add a regression test verifying that repeated
action changes do not increase the receiver count.

Pick-to: 6.11
Fixes: QTBUG-147826
Change-Id: I0f466888129176b794660140ea610bdf10500247
Reviewed-by: Axel Spoerl <[email protected]>
(cherry picked from commit 4b30fc623b238f895785d50d68047b4a12bfc22f)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>
https://invent.kde.org/qt/qt/qtbase/-/commit/a6146bc05354345a31d600be1085d536781516e3

Git commit 617242bba272518b57f7c201d63af299abcb877b by Qt Cherry-pick Bot (on behalf of Aurélien Brooke) on 30/07/2026 at 05:34..
QDoubleValidator: handle infinite bounds in StandardNotation

QDoubleValidator uses infinite bounds by default. When one input falls
outside a one-sided range in StandardNotation, validateWithLocale()
derives the permitted number of integer digits from the larger absolute
bound.

Commit a79de46ac59e045fbbbb8e0490ea6981b041be73 (6.5) changed this
calculation to pass the bound through qFloor() before convertDoubleTo(),
so that a fractional bound would not cause the digit-count check to be
skipped. However, qFloor() returns int. Passing an infinite bound, or a
finite bound outside int's range, therefore causes undefined behavior
during conversion to int.

Commit df97b6b2de6282bd6422f1e531a42475dadc980d (6.10) added range
assertions to qFloor(), correctly exposing this undefined behavior as a
fatal assertion in debug builds.

Use std::floor() to preserve the floating-point type. convertDoubleTo()
already handles infinities and values outside qlonglong's range safely,
so the digit-count check is simply skipped when the bound cannot be
represented.

Add regression coverage for ranges with either an infinite top or an
infinite bottom.

Pick-to: 6.11
Change-Id: I07bb3e922c12518920b74a8a4f16ce32c3cb967c
Reviewed-by: Edward Welbourne <[email protected]>
(cherry picked from commit dff034773aa1f7c14929f38412844ad19e7c3de7)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>
https://invent.kde.org/qt/qt/qtbase/-/commit/617242bba272518b57f7c201d63af299abcb877b