vim-patch:8.1.2140: "gk" and "gj" do not work correctly in number column #11208

Problem:    "gk" and "gj" do not work correctly in number column.
Solution:   Allow for a negative "curswant". (Zach Wegner, closes vim/vim#4969)
ceba3dd518

src/nvim/cursor.c

@@ -93,11 +93,12 @@ int coladvance(colnr_T wcol)
 
 static int coladvance2(
     pos_T *pos,
-    bool addspaces,                /* change the text to achieve our goal? */
+    bool addspaces,               // change the text to achieve our goal?
-    bool finetune,                 /* change char offset for the exact column */
+    bool finetune,                // change char offset for the exact column
-    colnr_T wcol                   /* column to move to */
+    colnr_T wcol_arg              // column to move to (can be negative)
 )
 {
+  colnr_T wcol = wcol_arg;
   int idx;
   char_u      *ptr;
   char_u      *line;
@@ -165,6 +166,7 @@ static int coladvance2(
 
     if (virtual_active()
         && addspaces
+        && wcol >= 0
         && ((col != wcol && col != wcol + 1) || csize > 1)) {
       /* 'virtualedit' is set: The difference between wcol and col is
        * filled with spaces. */
@@ -244,8 +246,9 @@ static int coladvance2(
     mark_mb_adjustpos(curbuf, pos);
   }
 
-  if (col < wcol)
+  if (wcol < 0 || col < wcol) {
     return FAIL;
+  }
   return OK;
 }
 

src/nvim/normal.c

@@ -3925,15 +3925,17 @@ static bool nv_screengo(oparg_T *oap, int dir, long dist)
         n = ((linelen - width1 - 1) / width2 + 1) * width2 + width1;
       else
         n = width1;
-      if (curwin->w_curswant > (colnr_T)n + 1)
+      if (curwin->w_curswant >= n) {
-        curwin->w_curswant -= ((curwin->w_curswant - n) / width2 + 1)
+        curwin->w_curswant = n - 1;
-                              * width2;
+      }
     }
 
     while (dist--) {
       if (dir == BACKWARD) {
-        if (curwin->w_curswant > width2) {
+        if (curwin->w_curswant >= width1) {
-          // move back within line
+          // Move back within the line. This can give a negative value
+          // for w_curswant if width1 < width2 (with cpoptions+=n),
+          // which will get clipped to column 0.
           curwin->w_curswant -= width2;
         } else {
           // to previous line
@@ -3973,6 +3975,13 @@ static bool nv_screengo(oparg_T *oap, int dir, long dist)
           }
           curwin->w_cursor.lnum++;
           curwin->w_curswant %= width2;
+          // Check if the cursor has moved below the number display
+          // when width1 < width2 (with cpoptions+=n). Subtract width2
+          // to get a negative value for w_curswant, which will get
+          // clipped to column 0.
+          if (curwin->w_curswant >= width1) {
+            curwin->w_curswant -= width2;
+          }
           linelen = linetabsize(get_cursor_line_ptr());
         }
       }

src/nvim/testdir/test_normal.vim

@@ -2813,4 +2813,29 @@ func Test_normal_gk()
   call assert_equal(95, virtcol('.'))
   bw!
   bw!
+
+  " needs 80 column new window
+  new
+  vert 80new
+  set number
+  set numberwidth=10
+  set cpoptions+=n
+  put =[repeat('0',90), repeat('1',90)]
+  norm! 075l
+  call assert_equal(76, col('.'))
+  norm! gk
+  call assert_equal(1, col('.'))
+  norm! gk
+  call assert_equal(76, col('.'))
+  norm! gk
+  call assert_equal(1, col('.'))
+  norm! gj
+  call assert_equal(76, col('.'))
+  norm! gj
+  call assert_equal(1, col('.'))
+  norm! gj
+  call assert_equal(76, col('.'))
+  bw!
+  bw!
+  set cpoptions& number& numberwidth&
 endfunc