Make editor::Rewrap respect paragraphs (#32046)

Closes #32021 

Release Notes:

- Changed the behavior of `editor::Rewrap` to not join paragraphs
together.

crates/editor/src/editor.rs

@@ -10873,14 +10873,54 @@ impl Editor {
     pub fn rewrap_impl(&mut self, options: RewrapOptions, cx: &mut Context<Self>) {
         let buffer = self.buffer.read(cx).snapshot(cx);
         let selections = self.selections.all::<Point>(cx);
-        let mut selections = selections.iter().peekable();
+
+        // Shrink and split selections to respect paragraph boundaries.
+        let ranges = selections.into_iter().flat_map(|selection| {
+            let language_settings = buffer.language_settings_at(selection.head(), cx);
+            let language_scope = buffer.language_scope_at(selection.head());
+
+            let Some(start_row) = (selection.start.row..=selection.end.row)
+                .find(|row| !buffer.is_line_blank(MultiBufferRow(*row)))
+            else {
+                return vec![];
+            };
+            let Some(end_row) = (selection.start.row..=selection.end.row)
+                .rev()
+                .find(|row| !buffer.is_line_blank(MultiBufferRow(*row)))
+            else {
+                return vec![];
+            };
+
+            let mut row = start_row;
+            let mut ranges = Vec::new();
+            while let Some(blank_row) =
+                (row..end_row).find(|row| buffer.is_line_blank(MultiBufferRow(*row)))
+            {
+                let next_paragraph_start = (blank_row + 1..=end_row)
+                    .find(|row| !buffer.is_line_blank(MultiBufferRow(*row)))
+                    .unwrap();
+                ranges.push((
+                    language_settings.clone(),
+                    language_scope.clone(),
+                    Point::new(row, 0)..Point::new(blank_row - 1, 0),
+                ));
+                row = next_paragraph_start;
+            }
+            ranges.push((
+                language_settings.clone(),
+                language_scope.clone(),
+                Point::new(row, 0)..Point::new(end_row, 0),
+            ));
+
+            ranges
+        });
 
         let mut edits = Vec::new();
         let mut rewrapped_row_ranges = Vec::<RangeInclusive<u32>>::new();
 
-        while let Some(selection) = selections.next() {
-            let mut start_row = selection.start.row;
-            let mut end_row = selection.end.row;
+        for (language_settings, language_scope, range) in ranges {
+            let mut start_row = range.start.row;
+            let mut end_row = range.end.row;
 
             // Skip selections that overlap with a range that has already been rewrapped.
             let selection_range = start_row..end_row;
@@ -10891,7 +10931,7 @@ impl Editor {
                 continue;
             }
 
-            let tab_size = buffer.language_settings_at(selection.head(), cx).tab_size;
+            let tab_size = language_settings.tab_size;
 
             // Since not all lines in the selection may be at the same indent
             // level, choose the indent size that is the most common between all
@@ -10922,25 +10962,20 @@ impl Editor {
             let mut line_prefix = indent_size.chars().collect::<String>();
 
             let mut inside_comment = false;
-            if let Some(comment_prefix) =
-                buffer
-                    .language_scope_at(selection.head())
-                    .and_then(|language| {
-                        language
-                            .line_comment_prefixes()
-                            .iter()
-                            .find(|prefix| buffer.contains_str_at(indent_end, prefix))
-                            .cloned()
-                    })
-            {
+            if let Some(comment_prefix) = language_scope.and_then(|language| {
+                language
+                    .line_comment_prefixes()
+                    .iter()
+                    .find(|prefix| buffer.contains_str_at(indent_end, prefix))
+                    .cloned()
+            }) {
                 line_prefix.push_str(&comment_prefix);
                 inside_comment = true;
             }
 
-            let language_settings = buffer.language_settings_at(selection.head(), cx);
             let allow_rewrap_based_on_language = match language_settings.allow_rewrap {
                 RewrapBehavior::InComments => inside_comment,
-                RewrapBehavior::InSelections => !selection.is_empty(),
+                RewrapBehavior::InSelections => !range.is_empty(),
                 RewrapBehavior::Anywhere => true,
             };
 
@@ -10951,11 +10986,12 @@ impl Editor {
                 continue;
             }
 
-            if selection.is_empty() {
+            if range.is_empty() {
                 'expand_upwards: while start_row > 0 {
                     let prev_row = start_row - 1;
                     if buffer.contains_str_at(Point::new(prev_row, 0), &line_prefix)
                         && buffer.line_len(MultiBufferRow(prev_row)) as usize > line_prefix.len()
+                        && !buffer.is_line_blank(MultiBufferRow(prev_row))
                     {
                         start_row = prev_row;
                     } else {
@@ -10967,6 +11003,7 @@ impl Editor {
                     let next_row = end_row + 1;
                     if buffer.contains_str_at(Point::new(next_row, 0), &line_prefix)
                         && buffer.line_len(MultiBufferRow(next_row)) as usize > line_prefix.len()
+                        && !buffer.is_line_blank(MultiBufferRow(next_row))
                     {
                         end_row = next_row;
                     } else {