ListBox/InputTextMultiline: Better optimized when clipped / non-visible.

DragScalarN, SliderScalarN, InputScalarN: Removed unnecessary string id after the integer PushID() calls.

Minor tweaks to reduce false positive of PVS Studio static analyzer.

Menus: Tweaked horizontal overlap between parent and child menu (to help convey relative depth) from using style.ItemSpacing.x to style.ItemInnerSpacing.x, the later being expected to be smaller. (#1086)

Plot: Register an ID to take the click the same way as other framed widgets. Set HoveredId in the FramePadding zone (between inner_bb and frame_bb).

Internals: Selectable: Fixed rendering width miscalculation when starting pos is not line start pos, which would generally be unnoticeable. Could affect group lock X with a smaller SetCursorPos value but that's unlikely to be used.

Internals: Removed unnecessary code.

Tabs: Moved Tab List Popup to left-side to match docking button. Highlight selected tab. (#261, #351)

Tabs: Non-docking tab bars are storing names to allow tab list button + whole style scaling. Added ImGuiTabBarFlags_TabListPopupButton flag to show a popup button on manual tab bars. Locking FramePadding for the scope of a tab-bar to avoid sheering/clipping of tab item. Made scaling of tab ellipsis less awkward. (#261, #351)

RadioButton: Fixed label horizontal alignment to precisely match Checkbox(). + Internals: Checkbox, RadioButton: Single call to ItemSize() for flow layout purpose.

Internals: DragScalar, SliderScalar: Calling ItemSize before ItemAdd as with every other widgets so we can more easily rearrange the signature of ItemXXX functions (toward allowing non-rounded sizes for scaling and flow layout).

Internals: Minor changes to TreeNodeBehavior() and Selectable() for the benefit of fhe range_select branch. (#1861)

Internals: Track ActiveIdHasBeenPressed (similar to ActiveIdHasBeenEdited). This is currently mostly for the benefit of the range_select branch. (#1861)

Internals: InputScalarAsWidgetReplacement: Fixed seemingly unnecessary calling of SetActiveID/SetHoveredID every frame, which in turns allow us to remove the g.ActiveIdAllow/Block settings duplicated.

InputText: Fixed a bug where ESCAPE would be first captured by the Keyboard Navigation code. (#2321, #787)

InputText: Fixed a bug where ESCAPE would not restore the initial value in all situations. (#2321) [@relick]

imgui-test: Added extra item info callbacks. Using nav_bb for interactions when possible. Comments, Demo tweaks.

Persistently fixing some PVS-Studio static analyzer false positive warnings.

Using IM_UNUSED() macro.

Fix various XCode and PVS-Studio static analyzer warnings (#2309)

Fixed range-version of PushID() and GetID() not honoring the ### operator to restart from the seed value.

Removed trailing spaces (#2038, #2299)

Added checks for "zero-as-null-pointer-constant" warnings for older Clang (#2299, followup to #2277)

Various tweaks and fixes as suggested by PVS Studio (thanks PVS Studio!)

Version 1.68 WIP

Version 1.67

DragFloat: Fixed broken mouse direction change with power!=1.0. (#2174, #2206) [@Joshhua5]

Added a bunch of diagnostic ignore to cope with Clang -Weverything being absurd. Also fixed two legit warnings. (#2277)

ImVector: Made a struct. Using T/T* in the code instead of value_type/iterator. Renamed index_from_pointer() to index_from_ptr() (was not documented, added in 1.63, users not supposed to use ImVector, hopefully not a big deal).

Minot internal tweaks, comments