From 9c3c6a1c22db065512c5563e9ed1c9dca869c886 Mon Sep 17 00:00:00 2001
From: Michael Davis
Date: Sun, 4 Sep 2022 21:34:49 -0500
Subject: Fix off-by-one in extend_line_above (#3689)

`extend_line_above` (and `extend_line` when facing backwards) skip
a line when the current range does not fully cover a line.

Before this change:

    foo
    b#[|a]#r
    baz

With `extend_line_above` or `extend_line` selected the line above.

    #[|foo
    bar]#
    baz

Which is inconsistent with `extend_line_below`. This commit changes
the behavior to select the current line when it is not already
selected.

    foo
    #[|bar]#
    baz

Then further calls of `extend_line_above` extend the selection up
line-wise.---
 helix-term/src/commands.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 906f201a..babfb2c8 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -1971,7 +1971,7 @@ fn extend_line_impl(cx: &mut Context, extend: Extend) {
         let (start_line, end_line) = range.line_range(text.slice(..));
 
         let start = text.line_to_char(match extend {
-            Extend::Above => start_line.saturating_sub(count),
+            Extend::Above => start_line.saturating_sub(count - 1),
             Extend::Below => start_line,
         });
         let end = text.line_to_char(
@@ -1985,7 +1985,7 @@ fn extend_line_impl(cx: &mut Context, extend: Extend) {
         // extend to previous/next line if current line is selected
         let (anchor, head) = if range.from() == start && range.to() == end {
             match extend {
-                Extend::Above => (end, text.line_to_char(start_line.saturating_sub(count + 1))),
+                Extend::Above => (end, text.line_to_char(start_line.saturating_sub(count))),
                 Extend::Below => (
                     start,
                     text.line_to_char((end_line + count + 1).min(text.len_lines())),
-- 
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