Wrong display with 'smoothscroll' when emptying quickfix list #16678

Job	Run time
macos (tiny, macos-12)	1m 16s
macos (tiny, macos-14)	48s
linux (tiny, clang, native)	2m 38s
macos (normal, macos-12)	7m 15s
linux (tiny, gcc, native)	2m 31s
macos (normal, macos-14)	4m 32s
linux (normal, clang, native)	5m 30s
macos (huge, macos-12)	13m 48s
linux (normal, gcc, native)	5m 54s
linux (huge, clang, native)	9m 25s
windows (HUGE, msvc, no, no, x64, stable)	5m 48s
macos (huge, macos-14)	12m 54s
linux (huge, gcc, native)	11m 17s
windows (HUGE, mingw, yes, yes, x86, stable, yes)	10m 14s
linux (tiny, clang, nogui)	2m 13s
windows (HUGE, msvc, no, yes, x86)	7m 30s
windows (HUGE, mingw, yes, no, x64, yes)	9m 5s
linux (tiny, gcc, nogui)	2m 19s
windows (NORMAL, msvc, yes, no, x86)	6m 37s
linux (normal, gcc, i386, ./src/shadow)	6m 11s
windows (NORMAL, mingw, no, yes, x64)	8m 38s
linux (huge, gcc, uchar, testgui, true, dynamic)	9m 35s
windows (TINY, msvc, yes, yes, x64)	2m 8s
linux (huge, clang, asan, 5.1)	16m 38s
windows (TINY, mingw, no, no, x86)	2m 50s
linux (huge, gcc, unittests, true)	3m 16s
linux (normal, gcc, vimtags)	2m 31s
	2h 53m 21s

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