It appears that the shift-delete key escape sequence is not being generated
because there's no mapping for it in screen-256color, causing the test to fail.
Switch to using f1 for the test.
Commit 3b30d92b6 (Commit transient edit when closing pager, 2022-08-31)
inadvertently introduced two regressions to history search:
1. It made Escape keeps the selected history entry,
instead of restoring the commandline before history search.
2. It made history search commands add undo entries.
Fix both of this issues.
A history search ends when you move the cursor, but the commandline inserted by
history search is still marked as transient. This means that the next history
search will clear the transient commandline. This means we are dropping an undo
point, for example:
echo 11
echo 1
echo autosuggestion
echo^P # commandline is "echo 1"
^A # stop history search
^P # commandline is "echo 11"
^Z # Bug: commandline goes back to "echo", but it should be "echo 1"
In the worst case, we are switching from line-search to token-search (see
the attached test case). Clearing the transient edit means the line is gone
and only the token is left on the command line.
