fix(extmarks): handle inline virt_text with empty chunk (#24005)

2 files changed, 61 insertions, 13 deletions

diff --git a/src/nvim/drawline.c b/src/nvim/drawline.c
index 280c1d6994..eb5de14f32 100644
--- a/src/nvim/drawline.c
+++ b/src/nvim/drawline.c
@@ -871,9 +871,15 @@ static void apply_cursorline_highlight(win_T *wp, winlinevars_T *wlv)
 
 static void handle_inline_virtual_text(win_T *wp, winlinevars_T *wlv, ptrdiff_t v, bool *do_save)
 {
-  while (true) {
-    // we could already be inside an existing inline text with multiple chunks
-    if (!(wlv->virt_inline_i < kv_size(wlv->virt_inline))) {
+  if (wlv->n_extra == 0 || !wlv->extra_for_extmark) {
+    wlv->reset_extra_attr = false;
+  }
+
+  while (wlv->n_extra == 0) {
+    if (wlv->virt_inline_i >= kv_size(wlv->virt_inline)) {
+      // need to find inline virtual text
+      wlv->virt_inline = VIRTTEXT_EMPTY;
+      wlv->virt_inline_i = 0;
       DecorState *state = &decor_state;
       for (size_t i = 0; i < kv_size(state->active); i++) {
         DecorRange *item = &kv_A(state->active, i);
@@ -884,18 +890,16 @@ static void handle_inline_virtual_text(win_T *wp, winlinevars_T *wlv, ptrdiff_t
         }
         if (item->draw_col >= -1 && item->start_col == v) {
           wlv->virt_inline = item->decor.virt_text;
-          wlv->virt_inline_i = 0;
           item->draw_col = INT_MIN;
           break;
         }
       }
-    }
-
-    if (wlv->n_extra == 0 || !wlv->extra_for_extmark) {
-      wlv->reset_extra_attr = false;
-    }
-
-    if (wlv->n_extra <= 0 && wlv->virt_inline_i < kv_size(wlv->virt_inline)) {
+      if (!kv_size(wlv->virt_inline)) {
+        // no more inline virtual text here
+        break;
+      }
+    } else {
+      // already inside existing inline virtual text with multiple chunks
       VirtTextChunk vtc = kv_A(wlv->virt_inline, wlv->virt_inline_i);
       wlv->p_extra = vtc.text;
       wlv->n_extra = (int)strlen(wlv->p_extra);
@@ -932,7 +936,6 @@ static void handle_inline_virtual_text(win_T *wp, winlinevars_T *wlv, ptrdiff_t
         }
       }
     }
-    break;
   }
 }
 
diff --git a/test/functional/ui/decorations_spec.lua b/test/functional/ui/decorations_spec.lua
index cbf0178d28..36c414e58f 100644
--- a/test/functional/ui/decorations_spec.lua
+++ b/test/functional/ui/decorations_spec.lua
@@ -1618,6 +1618,51 @@ describe('decorations: inline virtual text', function()
     ]]}
   end)
 
+  it('works with empty chunk', function()
+    insert(example_text)
+    feed 'gg'
+    screen:expect{grid=[[
+      ^for _,item in ipairs(items) do                    |
+          local text, hl_id_cell, count = unpack(item)  |
+          if hl_id_cell ~= nil then                     |
+              hl_id = hl_id_cell                        |
+          end                                           |
+          for _ = 1, (count or 1) do                    |
+              local cell = line[colpos]                 |
+              cell.text = text                          |
+              cell.hl_id = hl_id                        |
+                                                        |
+    ]]}
+
+    meths.buf_set_extmark(0, ns, 1, 14, {virt_text={{''}, {': ', 'Special'}, {'string', 'Type'}}, virt_text_pos='inline'})
+    screen:expect{grid=[[
+      ^for _,item in ipairs(items) do                    |
+          local text{10:: }{3:string}, hl_id_cell, count = unpack|
+      (item)                                            |
+          if hl_id_cell ~= nil then                     |
+              hl_id = hl_id_cell                        |
+          end                                           |
+          for _ = 1, (count or 1) do                    |
+              local cell = line[colpos]                 |
+              cell.text = text                          |
+                                                        |
+    ]]}
+
+    feed('jf,')
+    screen:expect{grid=[[
+      for _,item in ipairs(items) do                    |
+          local text{10:: }{3:string}^, hl_id_cell, count = unpack|
+      (item)                                            |
+          if hl_id_cell ~= nil then                     |
+              hl_id = hl_id_cell                        |
+          end                                           |
+          for _ = 1, (count or 1) do                    |
+              local cell = line[colpos]                 |
+              cell.text = text                          |
+                                                        |
+    ]]}
+  end)
+
   it('cursor positions are correct with multiple inline virtual text', function()
     insert('12345678')
     meths.buf_set_extmark(0, ns, 0, 4,
@@ -2013,7 +2058,7 @@ bbbbbbb]])
       ]]}
   end)
 
-  it('cursor position is correct when inserting around virtual texts with both left and right gravity ', function()
+  it('cursor position is correct when inserting around virtual texts with both left and right gravity', function()
     insert('foo foo foo foo')
     meths.buf_set_extmark(0, ns, 0, 8, { virt_text = {{ '>>', 'Special' }}, virt_text_pos = 'inline', right_gravity = false })
     meths.buf_set_extmark(0, ns, 0, 8, { virt_text = {{ '<<', 'Special' }}, virt_text_pos = 'inline', right_gravity = true })