Unable to proprely drag a imgui window outside of glfw window on Xubuntu (Ubuntu/Linux)

[NicolasFirmo]

Dear ImGui 1.77 WIP (17601)
--------------------------------
sizeof(size_t): 8, sizeof(ImDrawIdx): 2, sizeof(ImDrawVert): 20
define: __cplusplus=201703
define: __linux__
define: __GNUC__=7
define: IMGUI_HAS_VIEWPORT
define: IMGUI_HAS_DOCK
--------------------------------
io.BackendPlatformName: imgui_impl_glfw
io.BackendRendererName: imgui_impl_opengl3
io.ConfigFlags: 0x00000441
 NavEnableKeyboard
 DockingEnable
 ViewportsEnable
io.ConfigViewportsNoDecoration
io.ConfigInputTextCursorBlink
io.ConfigWindowsResizeFromEdges
io.ConfigWindowsMemoryCompactTimer = 60.0f
io.BackendFlags: 0x0000140E
 HasMouseCursors
 HasSetMousePos
 PlatformHasViewports
 RendererHasVtxOffset
 RendererHasViewports
--------------------------------
io.Fonts: 1 fonts, Flags: 0x00000000, TexSize: 512,64
io.DisplaySize: 640.00,480.00
io.DisplayFramebufferScale: 1.00,1.00
--------------------------------
style.WindowPadding: 8.00,8.00
style.WindowBorderSize: 1.00
style.FramePadding: 4.00,3.00
style.FrameRounding: 0.00
style.FrameBorderSize: 0.00
style.ItemSpacing: 8.00,4.00
style.ItemInnerSpacing: 4.00,4.00

Version/Branch of Dear ImGui:

Version: v1.76
Branch: docking

Back-end/Renderer/Compiler/OS

Back-ends: imgui_impl_glfw.cpp + imgui_impl_opengl3.cpp
Compiler: g++ (gcc)
Operating System: Xubuntu 18.04

My Issue/Question:

I'm developing this Linux/Windows project (tested so far on Xubuntu 18.04 and Windows 10) and the following issue is only occurring on my Xubuntu:
When I try to drag a imgui window outside of my glfw window, as it reaches the border, causing the glfw window loses focus, it loses the dragging behaviour even though I'm still holding the mouse button.

Screenshots/Video

Standalone, minimal, complete and verifiable example: (see #2261)

I could reproduce the issue by compiling the example_glfw_opengl3's main.cpp

[rokups]

Hello @NicolasFirmo,
This is a known issue, a bug in GLFW. You can follow it at glfw/glfw#1562
If you absolutely need it fixed you may use a dirty workaround i have: rokups@c510c11
Or you may use SDL, it does not have this problem.

[ocornut]

I'll close this as duplicate of the discussion in #2117
I hope we can somehow merge a workaround on our side soon!

[ocornut]

This is now fixed by c347d69. Thanks everyone for the help, and @rokups, and sorry for taking so long to look at this workaround.