The resize recovery treated the first SIGWINCH of a session as a width
change (no prior width to compare against), running the Ctrl+L-style
viewport clear + _OUTPUT_HISTORY replay. The 2J clear preserves
scrollback, so everything in the deque printed a second copy below the
still-visible original. After --continue/--resume the deque holds the
whole "Previous Conversation" recap plus the first live exchange, so a
benign resize signal (GNOME Terminal tab bar appearing, monitor-scale
change, focus events) duplicated the entire conversation.
Seed the width baseline when the resize hook is installed, and replay
only on an observed width change. The baseline is read from app.output
— get_app() at install time is still the DummyApplication whose
DummyOutput reports a fake 80 columns, which would turn the first real
signal back into a phantom width change. A real initial maximize or
restore still differs from the seeded width and is still recovered
(#49120 behavior preserved; verified in a pty harness both ways).
Fixes#65293
halaprix
a22fbba340