project: Fix inlay hints duplicatig on chunk start (#41461)

Release Notes:

- N/A *or* Added/Fixed/Improved ...

crates/editor/src/inlays/inlay_hints.rs

@@ -2695,7 +2695,7 @@ let c = 3;"#
                 ),
                 (
                     "main.rs",
-                    lsp::Range::new(lsp::Position::new(50, 0), lsp::Position::new(100, 11))
+                    lsp::Range::new(lsp::Position::new(50, 0), lsp::Position::new(100, 0))
                 ),
             ],
             lsp_request_ranges
@@ -2754,7 +2754,7 @@ let c = 3;"#
                 ),
                 (
                     "main.rs",
-                    lsp::Range::new(lsp::Position::new(50, 0), lsp::Position::new(100, 11))
+                    lsp::Range::new(lsp::Position::new(50, 0), lsp::Position::new(100, 0))
                 ),
             ],
             lsp_request_ranges

crates/project/src/lsp_store.rs

@@ -6608,9 +6608,9 @@ impl LspStore {
             return HashMap::default();
         }
 
-        let last_chunk_number = applicable_chunks.len() - 1;
+        let last_chunk_number = existing_inlay_hints.buffer_chunks_len() - 1;
 
-        for (i, row_chunk) in applicable_chunks.into_iter().enumerate() {
+        for row_chunk in applicable_chunks {
             match (
                 existing_inlay_hints
                     .cached_hints(&row_chunk)
@@ -6623,7 +6623,7 @@ impl LspStore {
                     .cloned(),
             ) {
                 (None, None) => {
-                    let end = if last_chunk_number == i {
+                    let end = if last_chunk_number == row_chunk.id {
                         Point::new(row_chunk.end, buffer_snapshot.line_len(row_chunk.end))
                     } else {
                         Point::new(row_chunk.end, 0)

crates/project/src/lsp_store/inlay_hint_cache.rs

@@ -67,7 +67,7 @@ struct HintForId {
 /// <https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#inlayHintParams>
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct BufferChunk {
-    id: usize,
+    pub id: usize,
     pub start: BufferRow,
     pub end: BufferRow,
 }
@@ -218,4 +218,8 @@ impl BufferInlayHints {
         debug_assert_eq!(*hint_id, id, "Invalid pointer {hint_for_id:?}");
         Some(hint)
     }
+
+    pub fn buffer_chunks_len(&self) -> usize {
+        self.buffer_chunks.len()
+    }
 }