Added IsItemDeactivatedAfterChange() if the last item was active previously, isn't anymore, and during its active state modified a value. Note that you may still get false positive. (#820, #956, #1875)

Internals: Added GetItemID(), GetFocusID() for consistency. Made GetActiveID() inline. Comments, fixed typos, demo tweaks.

Added IsItemDeactivated() to query if the last item was active previously but isn't anymore. Useful for Undo/Redo patterns. (#820, #956, #1875)

Comments

Comments, documentation

Big example binding refactor (manually imported from Viewport branch, stripped out of Viewport code). (#1870) ...

Read examples/README.txt for some details.
ImDrawData: Added DisplayPos, DisplaySize fields honored by all backends (not strictly necessary to honor just now, but doing it to be ahead)

Nav: Addendum: only set io.WantSetMousePos if necessary. (#1867)

Nav: Removed an unnecessary assertion that could fail when using Mouse and Keyboard simultaneously with the NavEnableSetMousePos flag. (#1867)

SliderFloat(): When using keyboard/gamepad and a zero precision format string (e.g. "%.0f"), always step in integer units. (#1866)

Popup: Improved handling of (erroneously) repeating calls to OpenPopup() to not fully close/re-open the popup so its child popups won't get closed. (#1497, #1533, #1865). ...

Followup/fix the change made in deab2ab

Readme, FAQ tweaks (#1807)

Added GetGlyphRangesChineseSimplifiedCommon() helper that returns a list of ~2500 most common Simplified Chinese characters. Renamed GetGlyphRangesChinese() to GetGlyphRangesChineseFull() to distinguish other variants and discourage using the full set. (#1859) ...

Changed the accumulative encoding to remove the implicit +1 which only saved a little space and made things more confusing.

TreeNodeEx(): The helper ImGuiTreeNodeFlags_CollapsingHeader flag now include ImGuiTreeNodeFlags_NoTreePushOnOpen. The flag was already set by CollapsingHeader(). The only difference is if you were using TreeNodeEx() manually with ImGuiTreeNodeFlags_CollapsingHeader and without ImGuiTreeNodeFlags_NoTreePushOnOpen. In which case you can remove the ImGuiTreeNodeFlags_NoTreePushOnOpen flag from your call (ImGuiTreeNodeFlags_CollapsingHeader & ~ImGuiTreeNodeFlags_NoTreePushOnOpen). (#1864)

InputTextMultiline(): Fixed double navigation highlight when scrollbar is active. (#787)

Nav: Fixed clipped scoring when exiting a NavFlattened child back to a parent item (clipping not desirable then). (followup and fix to c665c15). (#787)

Nav: Added support for PageUp/PageDown (explorer-style: first aim at bottom/top most item, when scroll a page worth of contents). (#787)

Changelog formatting update, Todo, comments. Tweak Child demo. Shuffle some code in NavUpdate().

Nav: When entering into a NavFlattened child we only consider the visible items for scoring (note that this only work assuming the NavFlattened child window has interactive items). Fixes accidentally hoping into a NavFlattened child. (#767)

Nav: NavFlattened: Fixed navigation miscrolling parent window when the current window is scrolling enough to keep the item in view. Fix feature added in e11610d6, typically affect large navigation steps (used by PageUp/PageDown). + comments (#787)

Internals: Nav: Removed ParentID from move result (unused, would need to be full-filled for PageUp/PageDown code) + FAQ typo fix.

Intensive FAQ answer for the million of people asking the same questions over and over again. (#1848, #1791, #1840, #1493, #1295)

Made mouse drag distance calculation more robust to invalid mouse position. (#1845)

Internals: Reintroducing LastActiveIdTimer because it is useful and to reduce merge conflicts. (#1537)

Internals: Added BeginDragDropTooltip() internal function to convey semantic (drag and drop tooltip doesn't get clipped within display boundaries). Revert part of 3218666. (#1739, #143).

Made drag source tooltip display at the same position as a regular tooltip to avoid discontinuity where dynamically swapping tooltip at the target site. Made drag source tooltip override previous tooltip if any. (#1739, #143).

Added ImGuiDragDropFlags_AcceptNoPreviewTooltip flag to disable drag source tooltip from the target site (#143)

Internals: Selectable: Renamed variables. Todo update.

Internals: PushItemFlag() flags are inherited by BeginChild().

Documentation: FAQ, ID Stack, Fonts (#1839, #1840), #1842)

Drag and Drop: Source doesn't report as hovered (at a lower-level). Source disable AllowOverlap flag if any set. (#143)