patch 8.1.2008: error for invalid range when using listener and undo

Problem:    Error for invalid range when using listener and undo. (Paul Jolly)
Solution:   Do not change the cursor before the lines are restored.
            (closes #4908)

diff --git a/src/testdir/test_listener.vim b/src/testdir/test_listener.vim
index 3aadeaa96d075d1afe88a93882611dc104fcc861..8c265be2db9f6d48853b7b0ad650b161b5f4865a 100644 (file)
--- a/src/testdir/test_listener.vim
+++ b/src/testdir/test_listener.vim
@@ -234,7 +234,7 @@ func Test_listener_garbage_collect()
   new
   let id = listener_add(function('MyListener', [{}]), bufnr(''))
   call test_garbagecollect_now()
-  " must not crach caused by invalid memory access
+  " must not crash caused by invalid memory access
   normal ia
   call assert_true(v:true)
 
@@ -268,3 +268,25 @@ func Test_listener_caches_buffer_line()
   iunmap <CR>
   set nocindent
 endfunc
+
+" Verify the fix for issue #4908
+func Test_listener_undo_line_number()
+  function DoIt()
+    " NOP
+  endfunction
+  function EchoChanges(bufnr, start, end, added, changes)
+    call DoIt()
+  endfunction
+
+  new
+  let lid = listener_add("EchoChanges")
+  call setline(1, ['a', 'b', 'c'])
+  set undolevels&  " start new undo block
+  call feedkeys("ggcG\<Esc>", 'xt')
+  undo
+
+  bwipe!
+  delfunc DoIt
+  delfunc EchoChanges
+  call listener_remove(lid)
+endfunc

diff --git a/src/undo.c b/src/undo.c
index e6bce43c214e09475a3b32da7ebcaecd2acc10d4..8145af0f7a51f3814256ebf6243887b980118e3e 100644 (file)
--- a/src/undo.c
+++ b/src/undo.c
@@ -2624,6 +2624,7 @@ u_undoredo(int undo)
     linenr_T   top, bot;
     linenr_T   lnum;
     linenr_T   newlnum = MAXLNUM;
+    pos_T      new_curpos = curwin->w_cursor;
     long       i;
     u_entry_T  *uep, *nuep;
     u_entry_T  *newlist = NULL;
@@ -2667,29 +2668,31 @@ u_undoredo(int undo)
        {
            unblock_autocmds();
            iemsg(_("E438: u_undo: line numbers wrong"));
-           changed();          /* don't want UNCHANGED now */
+           changed();          // don't want UNCHANGED now
            return;
        }
 
-       oldsize = bot - top - 1;    /* number of lines before undo */
-       newsize = uep->ue_size;     /* number of lines after undo */
+       oldsize = bot - top - 1;    // number of lines before undo
+       newsize = uep->ue_size;     // number of lines after undo
 
+       // Decide about the cursor position, depending on what text changed.
+       // Don't set it yet, it may be invalid if lines are going to be added.
        if (top < newlnum)
        {
-           /* If the saved cursor is somewhere in this undo block, move it to
-            * the remembered position.  Makes "gwap" put the cursor back
-            * where it was. */
+           // If the saved cursor is somewhere in this undo block, move it to
+           // the remembered position.  Makes "gwap" put the cursor back
+           // where it was.
            lnum = curhead->uh_cursor.lnum;
            if (lnum >= top && lnum <= top + newsize + 1)
            {
-               curwin->w_cursor = curhead->uh_cursor;
-               newlnum = curwin->w_cursor.lnum - 1;
+               new_curpos = curhead->uh_cursor;
+               newlnum = new_curpos.lnum - 1;
            }
            else
            {
-               /* Use the first line that actually changed.  Avoids that
-                * undoing auto-formatting puts the cursor in the previous
-                * line. */
+               // Use the first line that actually changed.  Avoids that
+               // undoing auto-formatting puts the cursor in the previous
+               // line.
                for (i = 0; i < newsize && i < oldsize; ++i)
                {
                    char_u *p = ml_get(top + 1 + i);
@@ -2702,28 +2705,29 @@ u_undoredo(int undo)
                if (i == newsize && newlnum == MAXLNUM && uep->ue_next == NULL)
                {
                    newlnum = top;
-                   curwin->w_cursor.lnum = newlnum + 1;
+                   new_curpos.lnum = newlnum + 1;
                }
                else if (i < newsize)
                {
                    newlnum = top + i;
-                   curwin->w_cursor.lnum = newlnum + 1;
+                   new_curpos.lnum = newlnum + 1;
                }
            }
        }
 
        empty_buffer = FALSE;
 
-       /* delete the lines between top and bot and save them in newarray */
+       /*
+        * Delete the lines between top and bot and save them in newarray.
+        */
        if (oldsize > 0)
        {
            if ((newarray = U_ALLOC_LINE(sizeof(undoline_T) * oldsize)) == NULL)
            {
                do_outofmem_msg((long_u)(sizeof(undoline_T) * oldsize));
-               /*
-                * We have messed up the entry list, repair is impossible.
-                * we have to free the rest of the list.
-                */
+
+               // We have messed up the entry list, repair is impossible.
+               // we have to free the rest of the list.
                while (uep != NULL)
                {
                    nuep = uep->ue_next;
@@ -2732,14 +2736,14 @@ u_undoredo(int undo)
                }
                break;
            }
-           /* delete backwards, it goes faster in most cases */
+           // delete backwards, it goes faster in most cases
            for (lnum = bot - 1, i = oldsize; --i >= 0; --lnum)
            {
-               /* what can we do when we run out of memory? */
+               // what can we do when we run out of memory?
                if (u_save_line(&newarray[i], lnum) == FAIL)
                    do_outofmem_msg((long_u)0);
-               /* remember we deleted the last line in the buffer, and a
-                * dummy empty line will be inserted */
+               // remember we deleted the last line in the buffer, and a
+               // dummy empty line will be inserted
                if (curbuf->b_ml.ml_line_count == 1)
                    empty_buffer = TRUE;
                ml_delete(lnum, FALSE);
@@ -2748,7 +2752,12 @@ u_undoredo(int undo)
        else
            newarray = NULL;
 
-       /* insert the lines in u_array between top and bot */
+       // make sure the cursor is on a valid line after the deletions
+       check_cursor_lnum();
+
+       /*
+        * Insert the lines in u_array between top and bot.
+        */
        if (newsize)
        {
            for (lnum = top, i = 0; i < newsize; ++i, ++lnum)
@@ -2766,7 +2775,7 @@ u_undoredo(int undo)
            vim_free((char_u *)uep->ue_array);
        }
 
-       /* adjust marks */
+       // adjust marks
        if (oldsize != newsize)
        {
            mark_adjust(top + 1, top + oldsize, (long)MAXLNUM,
@@ -2779,7 +2788,7 @@ u_undoredo(int undo)
 
        changed_lines(top + 1, 0, bot, newsize - oldsize);
 
-       /* set '[ and '] mark */
+       // set '[ and '] mark
        if (top + 1 < curbuf->b_op_start.lnum)
            curbuf->b_op_start.lnum = top + 1;
        if (newsize == 0 && top + 1 > curbuf->b_op_end.lnum)
@@ -2801,6 +2810,10 @@ u_undoredo(int undo)
        newlist = uep;
     }
 
+    // Set the cursor to the desired position.  Check that the line is valid.
+    curwin->w_cursor = new_curpos;
+    check_cursor_lnum();
+
     curhead->uh_entry = newlist;
     curhead->uh_flags = new_flags;
     if ((old_flags & UH_EMPTYBUF) && BUFEMPTY())

diff --git a/src/version.c b/src/version.c
index f0fe0591f526122c8bcb7b52bd8dd1f60bd0f54c..b797a59d199f42e5827610c8244999276687ae6c 100644 (file)
--- a/src/version.c
+++ b/src/version.c
@@ -757,6 +757,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2008,
 /**/
     2007,
 /**/