multi_buffer: Merge adjacent matches into a single excerpt when separated by only one line (#31708)

Kiran_Peraka and Antonio Scandurra created 

Closes #31252

Release Notes:

- Improved displaying of project search matches or diagnostics when the
excerpts are adjacent.

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>

Change summary

crates/multi_buffer/src/multi_buffer.rs       | 4 +++-
crates/multi_buffer/src/multi_buffer_tests.rs | 2 --
2 files changed, 3 insertions(+), 3 deletions(-)

Detailed changes

crates/multi_buffer/src/multi_buffer.rs 🔗 

@@ -1690,7 +1690,9 @@ impl MultiBuffer {
                     last_range.context.start <= range.context.start,
                     "Last range: {last_range:?} Range: {range:?}"
                 );
-                if last_range.context.end >= range.context.start {
+                if last_range.context.end >= range.context.start
+                    || last_range.context.end.row + 1 == range.context.start.row
+                {
                     last_range.context.end = range.context.end.max(last_range.context.end);
                     *counts.last_mut().unwrap() += 1;
                     continue;

crates/multi_buffer/src/multi_buffer_tests.rs 🔗 

@@ -1592,7 +1592,6 @@ fn test_set_excerpts_for_buffer_ordering(cx: &mut TestAppContext) {
              six
              seven
              eight
-             -----
              nine
              ten
              eleven
@@ -1848,7 +1847,6 @@ fn test_set_excerpts_for_buffer_rename(cx: &mut TestAppContext) {
         zero
         one
         two
-        -----
         three
         four
         five