Viewport: Fixed an assert on loss of valid mouse position while dragging a tooltip (would happen often when using debugger breakpoint). Not totally sure about best solution, may not be important.

Drag and Drop: Added ImGuiDragDropFlags_SourceAutoExpirePayload flag to force payload to expire if the source stops being submitted. (#1725, #143).

Drag and Drop: Clear payload buffers more consistently in ClearDragAndDrop() + BeginDragDropTargetCustom() can't succeed with hidden contents. (#143)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_opengl3.cpp
#	imgui.cpp

Drag and Drop: Payload stays available and under the mouse if the source stops being submitted, however the tooltip is replaced by "..." + moved FrameScopeActive = false at the bottom of EndFrame() for safety. (#1725)

InvisibleButton: Added an assert to catch common type of passing zero-sized dimensions. (#1983)

Made assertion more clear when trying to call Begin() outside of the NewFrame()..EndFrame() scope. (#1987)

Internals: Changed signature of ShadeVerts functions to remove pointers. (#1286, #1700, #1986)

Revert "Assert that fmt != NULL before calling vsnprintf (#1969)" ...

This reverts commit 84183f5.

Speculative va_copy() fix for old versions of GCC/Clang. (cannot repro) (#1085)

Visual Studio: calling into _vsnprintf. (#1085)

Internals: Fixed HoveredIdTimer so it is safe to call SetHoveredId() multiple times without altering the timer.

CollapseButton: Added hovering highlight + minor consistency tweaks.

Internals: Drag and Drop: default drop preview use a narrower clipping rectangle (no effect here, but other branches uses a narrow clipping rectangle that was too small so this is a fix for it) + Comments

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp
#	imgui_internal.h

Internals: Changed SplitterBehavior() signature to be consistent with other similar signatures. (#319).

Internals: Extracted part of Begin into UpdateWindowParentAndRootLinks(). Useful to call to keep state updated immediately (namely useful for docking) + small tidying up of imgui_internal.h

Assert that fmt != NULL before calling vsnprintf (#1969) ...

In the case of Visual Studio 15.6 + Windows SDK 10.0, vsnprintf() with NULL format string appears to corrupt the stack...

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp

Internals: Child windows that are clipped or part of a collapsed parent are not marked as collapsed anymore, but just a separate hidden marker set. We distinguish hiding for size measurement vs hiding for other reasons. Cleaned a little the end of Begin.

Nav: Tweaked CTRL+TAB to hide visual noise on fast switch + fading out screen dimming and highlight to make the experience less harsh

Nav: Tweaked CTRL+TAB to hide visual noise on fast switch + fading out screen dimming and highlight to make the experience less harsh

FAQ update

Internals: SplitterBehavior() added hover_visibility_delay parameter which is helpful to reduce visual noise. (#319)

Internals: Exposed NavScoreItemGetQuadrant() as ImGetDirQuadrantFromDelta() in imgui_internal.h

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_sdl.cpp
#	imgui.cpp

Made it possible to move a window by dragging from the Collapse button (past the drag threshold). Extracted some code out to a CollapseButton() function.

Internals: Renamed one of the arrow functions so their name don't collide.

Fixed horizontal mouse wheel not forwarding the request to the parent window if ImGuiWindowFlags_NoScrollWithMouse is set. (#1463, #1380, #1502)

Internals: Extracted part of NewFrame() into a UpdateMouseWheel() function.