vim-patch:8.1.0648: custom operators can't act upon forced motion

Problem:    Custom operators can't act upon a forced motion. (Christian
            Wellenbrock)
Solution:   Add the forced motion to the mode() result. (Christian Brabandt,
            closes vim/vim#3490)
https://github.com/vim/vim/commit/5976f8ff00efcb3e155a89346e44f2ad43d2405a

closes #8667
closes #9476

Christian Wellenbrock:

> For (most) built in text objects it's possible to force operation on
> them to be linewise, for example by using `dVab` (`:h o_V`,
> `motion_force`). When using custom text objects (defined as mappings
> by plugins for example), this doesn't currently work.
>
> Example:
>
>     onoremap x viw
>
> Open a file with a few lines each containing some words. With the
> cursor on any word, try:
>
> 1. `dw` (builtin) deletes some characters
> 2. `dVw` (builtin) deletes linewise
> 3. `dx` (from mapping) deletes some characters
> 4. `dVx` (from mapping) deletes some characters, but should delete
>    linewise

ref: https://github.com/wellle/targets.vim/issues/214
ref: https://gitter.im/neovim/neovim?at=5b379ff7f1664406610e7483

4 files changed, 66 insertions, 5 deletions

diff --git a/src/nvim/globals.h b/src/nvim/globals.h
index f2bd6408e8..f749c119cd 100644
--- a/src/nvim/globals.h
+++ b/src/nvim/globals.h
@@ -661,11 +661,13 @@ EXTERN int* (*iconv_errno)(void);
 ///    Visual_mode:    When State is NORMAL or INSERT.
 ///    finish_op  :    When State is NORMAL, after typing the operator and
 ///                    before typing the motion command.
+///    motion_force:   Last motion_force from do_pending_operator()
 EXTERN int State INIT(= NORMAL);        // This is the current state of the
                                         // command interpreter.
 
 EXTERN bool finish_op INIT(= false);    // true while an operator is pending
 EXTERN long opcount INIT(= 0);          // count for pending operator
+EXTERN int motion_force INIT(=0);       // motion force for pending operator
 
 // Ex Mode (Q) state
 EXTERN int exmode_active INIT(= 0);     // Zero, EXMODE_NORMAL or EXMODE_VIM.
diff --git a/src/nvim/normal.c b/src/nvim/normal.c
index 705dea4e88..29c5d27258 100644
--- a/src/nvim/normal.c
+++ b/src/nvim/normal.c
@@ -1445,8 +1445,10 @@ void do_pending_operator(cmdarg_T *cap, int old_col, bool gui_yank)
       oap->motion_type = kMTCharWise;
     } else if (oap->motion_force == Ctrl_V) {
       // Change line- or characterwise motion into Visual block mode.
-      VIsual_active = true;
-      VIsual = oap->start;
+      if (!VIsual_active) {
+        VIsual_active = true;
+        VIsual = oap->start;
+      }
       VIsual_mode = Ctrl_V;
       VIsual_select = false;
       VIsual_reselect = false;
@@ -2039,6 +2041,7 @@ void do_pending_operator(cmdarg_T *cap, int old_col, bool gui_yank)
       curwin->w_cursor = old_cursor;
     }
     clearop(oap);
+    motion_force = NUL;
   }
   curwin->w_p_lbr = lbr_saved;
 }
@@ -6389,8 +6392,8 @@ static void nv_visual(cmdarg_T *cap)
   /* 'v', 'V' and CTRL-V can be used while an operator is pending to make it
    * characterwise, linewise, or blockwise. */
   if (cap->oap->op_type != OP_NOP) {
-    cap->oap->motion_force = cap->cmdchar;
-    finish_op = false;          /* operator doesn't finish now but later */
+    motion_force = cap->oap->motion_force = cap->cmdchar;
+    finish_op = false;          // operator doesn't finish now but later
     return;
   }
 
diff --git a/src/nvim/state.c b/src/nvim/state.c
index d75f4038ae..bfd73050c3 100644
--- a/src/nvim/state.c
+++ b/src/nvim/state.c
@@ -113,7 +113,7 @@ int get_real_state(void)
 /// @returns[allocated] mode string
 char *get_mode(void)
 {
-  char *buf = xcalloc(3, sizeof(char));
+  char *buf = xcalloc(4, sizeof(char));
 
   if (VIsual_active) {
     if (VIsual_select) {
@@ -160,6 +160,8 @@ char *get_mode(void)
     buf[0] = 'n';
     if (finish_op) {
       buf[1] = 'o';
+      // to be able to detect force-linewise/blockwise/characterwise operations
+      buf[2] = (char)motion_force;
     }
   }
 
diff --git a/src/nvim/testdir/test_mapping.vim b/src/nvim/testdir/test_mapping.vim
index 247c01c98d..32593a423a 100644
--- a/src/nvim/testdir/test_mapping.vim
+++ b/src/nvim/testdir/test_mapping.vim
@@ -230,3 +230,57 @@ func Test_abbreviation_CR()
   delfunc Eatchar
   bw!
 endfunc
+
+func Test_motionforce_omap()
+  func GetCommand()
+    let g:m=mode(1)
+    let [g:lnum1, g:col1] = searchpos('-', 'Wb')
+    if g:lnum1 == 0
+        return "\<Esc>"
+    endif
+    let [g:lnum2, g:col2] = searchpos('-', 'W')
+    if g:lnum2 == 0
+        return "\<Esc>"
+    endif
+    return ":call Select()\<CR>"
+  endfunc
+  func Select()
+    call cursor([g:lnum1, g:col1])
+    exe "normal! 1 ". (strlen(g:m) == 2 ? 'v' : g:m[2])
+    call cursor([g:lnum2, g:col2])
+    execute "normal! \<BS>"
+  endfunc
+  new
+  onoremap <buffer><expr> i- GetCommand()
+  " 1) default omap mapping
+  %d_
+  call setline(1, ['aaa - bbb', 'x', 'ddd - eee'])
+  call cursor(2, 1)
+  norm di-
+  call assert_equal('no', g:m)
+  call assert_equal(['aaa -- eee'], getline(1, '$'))
+  " 2) forced characterwise operation
+  %d_
+  call setline(1, ['aaa - bbb', 'x', 'ddd - eee'])
+  call cursor(2, 1)
+  norm dvi-
+  call assert_equal('nov', g:m)
+  call assert_equal(['aaa -- eee'], getline(1, '$'))
+  " 3) forced linewise operation
+  %d_
+  call setline(1, ['aaa - bbb', 'x', 'ddd - eee'])
+  call cursor(2, 1)
+  norm dVi-
+  call assert_equal('noV', g:m)
+  call assert_equal([''], getline(1, '$'))
+  " 4) forced blockwise operation
+  %d_
+  call setline(1, ['aaa - bbb', 'x', 'ddd - eee'])
+  call cursor(2, 1)
+  exe "norm d\<C-V>i-"
+  call assert_equal("no\<C-V>", g:m)
+  call assert_equal(['aaabbb', 'x', 'dddeee'], getline(1, '$'))
+  bwipe!
+  delfunc Select
+  delfunc GetCommand
+endfunc