ADR 0122: The cursor on the line it selected

Status

Accepted

Context

Two reports.

V selected a line and put the caret on the line below it, with the status bar agreeing — it read Ln 4 for a selection of line 3.

And the command line could not be opened from the panel, so closing a panel with :q meant first going back to the buffer to be allowed to type it.

Decision

The linewise cursor sits on the last selected line

vimNormalizeLinewiseSelection() parked the cursor at the start of the line after the last selected one, because that is where the selection's range ends. The range was right; the caret was a line below what was highlighted.

Both ends now sit at the start of their own line, and vimVisualEnd() works the span out from the line numbers it already keeps. The cursor no longer has to carry the range.

Two things fell out of that:

The paint guard asked hasSelectionAt(), which is anchor != cursor. A linewise selection of one line now has both at the same offset and still covers the line, so a single-line V highlighted nothing. It asks what the operators ask instead — is there a range — which is the question that was always meant.

The column is not preserved: the cursor lands at column 1 of its line rather than keeping the column it had, where vim keeps it. A linewise selection has no column, and it is the line being wrong that was reported.

The command line belongs to the window

It was a viewport command, so it could only be opened by the buffer, and the buffer only hears keys when it has focus. :q to close a panel you are reading is the obvious thing to type and it was unreachable from there.

It is a window command now, like the buffer list and the jumplist. The command it opens still runs against the buffer in front, which is what makes :q close the panel (ADR 0118) rather than the buffer.

Consequences

Moving it exposed a latent bug in sequenceFor(), which turns a chord into a QKeySequence for a window shortcut. It spelled punctuation as words — Alt+Semicolon — and Qt only parses the symbol, Alt+;. An unparsed sequence is empty, and an empty sequence installs a shortcut that can never fire, with no error anywhere. Alt+; simply did nothing.

It had been harmless until now because every other window shortcut used letters or named keys. It uses the same spelling the help panel shows, which is the one Qt accepts.

All 220 vim conformance cases pass unchanged, which is what says the operator ranges survived the change to where the cursor sits: they test what V, Vj, Vd and Vy do to the text, and none of that moved.