1 files changed, 41 insertions, 42 deletions

diff --git a/src/nvim/mouse.c b/src/nvim/mouse.c
index e35385dd43..c4a31e0783 100644
--- a/src/nvim/mouse.c
+++ b/src/nvim/mouse.c
@@ -1849,56 +1849,55 @@ static void mouse_check_grid(colnr_T *vcolp, int *flagsp)
   int click_grid = mouse_grid;
   int click_row = mouse_row;
   int click_col = mouse_col;
-  int max_row = Rows;
-  int max_col = Columns;
-  bool multigrid = ui_has(kUIMultigrid);
-  colnr_T col_from_screen = -1;
 
+  // XXX: this doesn't change click_grid if it is 1, even with multigrid
   win_T *wp = mouse_find_win(&click_grid, &click_row, &click_col);
-  if (wp && multigrid) {
-    max_row = wp->w_grid_alloc.rows;
-    max_col = wp->w_grid_alloc.cols;
+  // Only use vcols[] after the window was redrawn.  Mainly matters
+  // for tests, a user would not click before redrawing.
+  if (wp == NULL || wp->w_redr_type != 0) {
+    return;
   }
+  ScreenGrid *gp = &wp->w_grid;
+  int start_row = 0;
+  int start_col = 0;
+  grid_adjust(&gp, &start_row, &start_col);
+  if (gp->handle != click_grid) {
+    return;
+  }
+  click_row += start_row;
+  click_col += start_col;
 
-  if (wp && mouse_row >= 0 && mouse_row < max_row
-      && mouse_col >= 0 && mouse_col < max_col) {
-    ScreenGrid *gp = multigrid ? &wp->w_grid_alloc : &default_grid;
-    int use_row = multigrid && mouse_grid == 0 ? click_row : mouse_row;
-    int use_col = multigrid && mouse_grid == 0 ? click_col : mouse_col;
-
-    if (gp->chars != NULL) {
-      const size_t off = gp->line_offset[use_row] + (size_t)use_col;
-
-      // Only use vcols[] after the window was redrawn.  Mainly matters
-      // for tests, a user would not click before redrawing.
-      if (wp->w_redr_type == 0) {
-        col_from_screen = gp->vcols[off];
-      }
+  colnr_T col_from_screen = -1;
 
-      if (col_from_screen == MAXCOL) {
-        // When clicking after end of line, still need to set correct curswant
-        size_t off_l = gp->line_offset[use_row];
-        if (gp->vcols[off_l] < MAXCOL) {
-          // Binary search to find last char in line
-          size_t off_r = off;
-          while (off_l < off_r) {
-            size_t off_m = (off_l + off_r + 1) / 2;
-            if (gp->vcols[off_m] < MAXCOL) {
-              off_l = off_m;
-            } else {
-              off_r = off_m - 1;
-            }
+  if (gp->chars != NULL
+      && click_row >= 0 && click_row < gp->rows
+      && click_col >= 0 && click_col < gp->cols) {
+    const size_t off = gp->line_offset[click_row] + (size_t)click_col;
+    col_from_screen = gp->vcols[off];
+
+    if (col_from_screen == MAXCOL) {
+      // When clicking after end of line, still need to set correct curswant
+      size_t off_l = gp->line_offset[click_row] + (size_t)start_col;
+      if (gp->vcols[off_l] < MAXCOL) {
+        // Binary search to find last char in line
+        size_t off_r = off;
+        while (off_l < off_r) {
+          size_t off_m = (off_l + off_r + 1) / 2;
+          if (gp->vcols[off_m] < MAXCOL) {
+            off_l = off_m;
+          } else {
+            off_r = off_m - 1;
           }
-          *vcolp = gp->vcols[off_r] + (int)(off - off_r);
-        } else {
-          // Shouldn't normally happen
-          *vcolp = MAXCOL;
         }
-      } else if (col_from_screen >= 0) {
-        // Use the virtual column from vcols[], it is accurate also after
-        // concealed characters.
-        *vcolp = col_from_screen;
+        *vcolp = gp->vcols[off_r] + (int)(off - off_r);
+      } else {
+        // Clicking on an empty line
+        *vcolp = click_col - start_col;
       }
+    } else if (col_from_screen >= 0) {
+      // Use the virtual column from vcols[], it is accurate also after
+      // concealed characters.
+      *vcolp = col_from_screen;
     }
   }