[PATCH 09/10] vi: improve operations involving paragraph movement

[Ron Yorston]

Movement by paragraph doesn't always involve whole lines.  If the
cursor is positioned in the middle of a line deleting to either end
of the paragraph will result in one partial line and zero or more
full lines.

Adjust the end of ranges delimited by paragraph movement to more
closely match what vi does.

function                                             old     new   delta
find_range                                           467     518     +51
at_eof                                                 -      49     +49
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 100/0)             Total: 100 bytes

Signed-off-by: Ron Yorston <rmy at pobox.com>
---
 editors/vi.c | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/editors/vi.c b/editors/vi.c
index 94a5506b3..deff3135f 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -3051,6 +3051,12 @@ static void int_handler(int sig)
 
 static void do_cmd(int c);
 
+static int at_eof(const char *s)
+{
+	// does 's' point to end of file, even with no terminating newline?
+	return ((s == end - 2 && s[1] == '\n') || s == end - 1);
+}
+
 static int find_range(char **start, char **stop, char c)
 {
 	char *save_dot, *p, *q, *t;
@@ -3064,7 +3070,7 @@ static int find_range(char **start, char **stop, char c)
 		buftype = WHOLE;
 		if (--cmdcnt > 0)
 			do_cmd('j');
-	} else if (strchr("^%$0bBeEfFtTh|\b\177", c)) {
+	} else if (strchr("^%$0bBeEfFtTh|{}\b\177", c)) {
 		// These cmds operate on char positions
 		buftype = PARTIAL;
 		do_cmd(c);		// execute movement cmd
@@ -3074,9 +3080,9 @@ static int find_range(char **start, char **stop, char c)
 		buftype = MULTI;
 		do_cmd(c);		// execute movement cmd
 		// step back one char, but not if we're at end of file
-		if (dot > p && !((dot == end - 2 && end[-1] == '\n') || dot == end - 1))
+		if (dot > p && !at_eof(dot))
 			dot--;
-	} else if (strchr("GHL+-jk{}\r\n", c)) {
+	} else if (strchr("GHL+-jk\r\n", c)) {
 		// these operate on whole lines
 		buftype = WHOLE;
 		do_cmd(c);		// execute movement cmd
@@ -3101,14 +3107,26 @@ static int find_range(char **start, char **stop, char c)
 		p = t;
 	}
 
+	// movements which don't include end of range
+	if (q > p) {
+		if (strchr("^0bBFTh|\b\177", c)) {
+			q--;
+		} else if (strchr("{}", c)) {
+			buftype = (p == begin_line(p) && (*q == '\n' || at_eof(q))) ?
+							WHOLE : MULTI;
+			if (!at_eof(q)) {
+				q--;
+				if (q > p && p != begin_line(p))
+					q--;
+			}
+		}
+	}
+
 	if (buftype == WHOLE) {
 		p = begin_line(p);
 		q = end_line(q);
 	}
 
-	// movements which don't include end of range
-	if (q > p && strchr("^0bBFTh|\b\177", c)) q--;
-
 	*start = p;
 	*stop = q;
 	dot = save_dot;
-- 
2.30.2