[git commit] vi: fix range selection by forward character motion

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=5bef6781fa434bd65558cefe950f670df34fea4e
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

Selection of ranges for change/delete/yank by forward character
motion commands (SPACE or 'l') was incorrect.  The range was
always one character whereas vi allows the size of the range to
be specified.

Fix this by executing the motion command the required number of times.
There is a complication when the range is at the end of a line.  We need
to distinguish between a range which excludes the last character and
one which includes it.  This requires comparing the actual range with
that expected from the command count.  (With the additional quirk that
a command count of zero is equivalent to a command count of one.)

function                                             old     new   delta
find_range                                           587     619     +32
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 32/0)               Total: 32 bytes

Signed-off-by: Ron Yorston <rmy at pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 editors/vi.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/editors/vi.c b/editors/vi.c
index 01597fa5e..adfb2b87c 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -3047,12 +3047,15 @@ static int find_range(char **start, char **stop, char c)
 		do_cmd(c);		// execute movement cmd
 		dot_end();		// find NL
 		q = dot;
-	} else {
-		// nothing -- this causes any other values of c to
-		// represent the one-character range under the
-		// cursor.  this is correct for ' ' and 'l', but
-		// perhaps no others.
-		//
+	} else /* if (c == ' ' || c == 'l') */ {
+		// forward motion by character
+		int tmpcnt = (cmdcnt ?: 1);
+		do_cmd(c);		// execute movement cmd
+		// exclude last char unless range isn't what we expected
+		// this indicates we've hit EOL
+		if (tmpcnt == dot - p)
+			dot--;
+		q = dot;
 	}
 	if (q < p) {
 		t = q;