vim-patch:8.2.3073: when cursor is move for block append wrong text is inserted

Problem:    When cursor is move for block append wrong text is inserted.
Solution:   Calculate an offset. (Christian Brabandt, closes vim/vim#8433,
            closes vim/vim#8288)
https://github.com/vim/vim/commit/4067bd3604215b48e4b4201e28f9e401b08418e4

3 files changed, 87 insertions, 23 deletions

diff --git a/src/nvim/ops.c b/src/nvim/ops.c
index f999b68236..68ce9824c7 100644
--- a/src/nvim/ops.c
+++ b/src/nvim/ops.c
@@ -580,6 +580,9 @@ static void block_insert(oparg_T *oap, char_u *s, int b_insert, struct block_def
       spaces -= off;
       count -= off;
     }
+    if (spaces < 0) {  // can happen when the cursor was moved
+      spaces = 0;
+    }
 
     assert(count >= 0);
     newp = (char_u *)xmalloc(STRLEN(oldp) + s_len + (size_t)count + 1);
@@ -2278,6 +2281,7 @@ void op_insert(oparg_T *oap, long count1)
   }
 
   t1 = oap->start;
+  const pos_T start_insert = curwin->w_cursor;
   (void)edit(NUL, false, (linenr_T)count1);
 
   // When a tab was inserted, and the characters in front of the tab
@@ -2315,26 +2319,30 @@ void op_insert(oparg_T *oap, long count1)
     if (oap->start.lnum == curbuf->b_op_start_orig.lnum
         && !bd.is_MAX
         && !did_indent) {
-      if (oap->op_type == OP_INSERT
-          && oap->start.col + oap->start.coladd
-          != curbuf->b_op_start_orig.col + curbuf->b_op_start_orig.coladd) {
-        int t = getviscol2(curbuf->b_op_start_orig.col,
-                           curbuf->b_op_start_orig.coladd);
-        oap->start.col = curbuf->b_op_start_orig.col;
-        pre_textlen -= t - oap->start_vcol;
-        oap->start_vcol = t;
-      } else if (oap->op_type == OP_APPEND
-                 && oap->end.col + oap->end.coladd
-                 >= curbuf->b_op_start_orig.col
-                 + curbuf->b_op_start_orig.coladd) {
-        int t = getviscol2(curbuf->b_op_start_orig.col,
-                           curbuf->b_op_start_orig.coladd);
-        oap->start.col = curbuf->b_op_start_orig.col;
+      const int t = getviscol2(curbuf->b_op_start_orig.col, curbuf->b_op_start_orig.coladd);
+
+      if (!bd.is_MAX) {
+        if (oap->op_type == OP_INSERT
+            && oap->start.col + oap->start.coladd
+            != curbuf->b_op_start_orig.col + curbuf->b_op_start_orig.coladd) {
+          oap->start.col = curbuf->b_op_start_orig.col;
+          pre_textlen -= t - oap->start_vcol;
+          oap->start_vcol = t;
+        } else if (oap->op_type == OP_APPEND
+                   && oap->end.col + oap->end.coladd
+                   >= curbuf->b_op_start_orig.col
+                   + curbuf->b_op_start_orig.coladd) {
+          oap->start.col = curbuf->b_op_start_orig.col;
+          // reset pre_textlen to the value of OP_INSERT
+          pre_textlen += bd.textlen;
+          pre_textlen -= t - oap->start_vcol;
+          oap->start_vcol = t;
+          oap->op_type = OP_INSERT;
+        }
+      } else if (bd.is_MAX && oap->op_type == OP_APPEND) {
         // reset pre_textlen to the value of OP_INSERT
         pre_textlen += bd.textlen;
         pre_textlen -= t - oap->start_vcol;
-        oap->start_vcol = t;
-        oap->op_type = OP_INSERT;
       }
     }
 
@@ -2376,15 +2384,27 @@ void op_insert(oparg_T *oap, long count1)
     firstline = ml_get(oap->start.lnum);
     const size_t len = STRLEN(firstline);
     colnr_T add = bd.textcol;
+    colnr_T offset = 0;  // offset when cursor was moved in insert mode
     if (oap->op_type == OP_APPEND) {
       add += bd.textlen;
+      // account for pressing cursor in insert mode when '$' was used
+      if (bd.is_MAX && start_insert.lnum == Insstart.lnum && start_insert.col > Insstart.col) {
+        offset = start_insert.col - Insstart.col;
+        add -= offset;
+        if (oap->end_vcol > offset) {
+          oap->end_vcol -= offset + 1;
+        } else {
+          // moved outside of the visual block, what to do?
+          return;
+        }
+      }
     }
     if ((size_t)add > len) {
       firstline += len;  // short line, point to the NUL
     } else {
       firstline += add;
     }
-    ins_len = (long)STRLEN(firstline) - pre_textlen;
+    ins_len = (long)STRLEN(firstline) - pre_textlen - offset;
     if (pre_textlen >= 0 && ins_len > 0) {
       ins_text = vim_strnsave(firstline, (size_t)ins_len);
       // block handled here
diff --git a/src/nvim/testdir/test_blockedit.vim b/src/nvim/testdir/test_blockedit.vim
index 38978ef689..7b56b1554f 100644
--- a/src/nvim/testdir/test_blockedit.vim
+++ b/src/nvim/testdir/test_blockedit.vim
@@ -81,4 +81,52 @@ func Test_blockinsert_delete()
   bwipe!
 endfunc
 
+func Test_blockappend_eol_cursor()
+  new
+  " Test 1 Move 1 char left
+  call setline(1, ['aaa', 'bbb', 'ccc'])
+  exe "norm! gg$\<c-v>2jA\<left>x\<esc>"
+  call assert_equal(['aaxa', 'bbxb', 'ccxc'], getline(1, '$'))
+  " Test 2 Move 2 chars left
+  sil %d
+  call setline(1, ['aaa', 'bbb', 'ccc'])
+  exe "norm! gg$\<c-v>2jA\<left>\<left>x\<esc>"
+  call assert_equal(['axaa', 'bxbb', 'cxcc'], getline(1, '$'))
+  " Test 3 Move 3 chars left (outside of the visual selection)
+  sil %d
+  call setline(1, ['aaa', 'bbb', 'ccc'])
+  exe "norm! ggl$\<c-v>2jA\<left>\<left>\<left>x\<esc>"
+  call assert_equal(['xaaa', 'bbb', 'ccc'], getline(1, '$'))
+  bw!
+endfunc
+
+func Test_blockappend_eol_cursor2()
+  new
+  " Test 1 Move 1 char left
+  call setline(1, ['aaaaa', 'bbb', 'ccccc'])
+  exe "norm! gg\<c-v>$2jA\<left>x\<esc>"
+  call assert_equal(['aaaaxa', 'bbbx', 'ccccxc'], getline(1, '$'))
+  " Test 2 Move 2 chars left
+  sil %d
+  call setline(1, ['aaaaa', 'bbb', 'ccccc'])
+  exe "norm! gg\<c-v>$2jA\<left>\<left>x\<esc>"
+  call assert_equal(['aaaxaa', 'bbbx', 'cccxcc'], getline(1, '$'))
+  " Test 3 Move 3 chars left (to the beginning of the visual selection)
+  sil %d
+  call setline(1, ['aaaaa', 'bbb', 'ccccc'])
+  exe "norm! gg\<c-v>$2jA\<left>\<left>\<left>x\<esc>"
+  call assert_equal(['aaxaaa', 'bbxb', 'ccxccc'], getline(1, '$'))
+  " Test 4 Move 3 chars left (outside of the visual selection)
+  sil %d
+  call setline(1, ['aaaaa', 'bbb', 'ccccc'])
+  exe "norm! ggl\<c-v>$2jA\<left>\<left>\<left>x\<esc>"
+  call assert_equal(['aaxaaa', 'bbxb', 'ccxccc'], getline(1, '$'))
+  " Test 5 Move 4 chars left (outside of the visual selection)
+  sil %d
+  call setline(1, ['aaaaa', 'bbb', 'ccccc'])
+  exe "norm! ggl\<c-v>$2jA\<left>\<left>\<left>\<left>x\<esc>"
+  call assert_equal(['axaaaa', 'bxbb', 'cxcccc'], getline(1, '$'))
+  bw!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/nvim/testdir/test_visual.vim b/src/nvim/testdir/test_visual.vim
index d05035b4e9..f95801cab5 100644
--- a/src/nvim/testdir/test_visual.vim
+++ b/src/nvim/testdir/test_visual.vim
@@ -866,11 +866,7 @@ func Test_visual_block_mode()
   %d _
   call setline(1, ['aaa', 'bbb', 'ccc'])
   exe "normal $\<C-V>2jA\<Left>x"
-  " BUG: Instead of adding x as the third character in all the three lines,
-  " 'a' is added in the second and third lines at the end. This bug is not
-  " reproducible if this operation is performed manually.
-  "call assert_equal(['aaxa', 'bbxb', 'ccxc'], getline(1, '$'))
-  call assert_equal(['aaxa', 'bbba', 'ccca'], getline(1, '$'))
+  call assert_equal(['aaxa', 'bbxb', 'ccxc'], getline(1, '$'))
   " Repeat the previous test but use 'l' to move the cursor instead of '$'
   call setline(1, ['aaa', 'bbb', 'ccc'])
   exe "normal! gg2l\<C-V>2jA\<Left>x"