diff --git a/src/buffer.c b/src/buffer.c
index 75116a9..1b5ae9f 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -4405,7 +4405,12 @@
 {
     int		i;
     win_T	*wp, *wpnext;
-    char_u	*opened;	/* array of flags for which args are open */
+    char_u	*opened;	/* Array of weight for which args are open:
+				 *  0: not opened
+				 *  1: opened in other tab
+				 *  2: opened in curtab
+				 *  3: opened in curtab and curwin
+				 */
     int		opened_len;	/* length of opened[] */
     int		use_firstwin = FALSE;	/* use first window for arglist */
     int		split_ret = OK;
@@ -4414,6 +4419,8 @@
     buf_T	*buf;
     tabpage_T	*tpnext;
     int		had_tab = cmdmod.tab;
+    win_T	*old_curwin, *last_curwin;
+    tabpage_T	*old_curtab, *last_curtab;
     win_T	*new_curwin = NULL;
     tabpage_T	*new_curtab = NULL;
 
@@ -4430,6 +4437,15 @@
     if (opened == NULL)
 	return;
 
+    /* Autocommands may do anything to the argument list.  Make sure it's not
+     * freed while we are working here by "locking" it.  We still have to
+     * watch out for its size to be changed. */
+    alist = curwin->w_alist;
+    ++alist->al_refcount;
+
+    old_curwin = curwin;
+    old_curtab = curtab;
+
 #ifdef FEAT_GUI
     need_mouse_correct = TRUE;
 #endif
@@ -4451,36 +4467,51 @@
 	    wpnext = wp->w_next;
 	    buf = wp->w_buffer;
 	    if (buf->b_ffname == NULL
-		    || buf->b_nwindows > 1
+		    || (!keep_tabs && buf->b_nwindows > 1)
 #ifdef FEAT_VERTSPLIT
 		    || wp->w_width != Columns
 #endif
 		    )
-		i = ARGCOUNT;
+		i = opened_len;
 	    else
 	    {
 		/* check if the buffer in this window is in the arglist */
-		for (i = 0; i < ARGCOUNT; ++i)
+		for (i = 0; i < opened_len; ++i)
 		{
-		    if (ARGLIST[i].ae_fnum == buf->b_fnum
-			    || fullpathcmp(alist_name(&ARGLIST[i]),
-					      buf->b_ffname, TRUE) & FPC_SAME)
+		    if (i < alist->al_ga.ga_len
+			    && (AARGLIST(alist)[i].ae_fnum == buf->b_fnum
+				|| fullpathcmp(alist_name(&AARGLIST(alist)[i]),
+					      buf->b_ffname, TRUE) & FPC_SAME))
 		    {
-			if (i < opened_len)
+			int weight = 1;
+
+			if (old_curtab == curtab)
 			{
-			    opened[i] = TRUE;
+			    ++weight;
+			    if (old_curwin == wp)
+				++weight;
+			}
+
+			if (weight > (int)opened[i])
+			{
+			    opened[i] = (char_u)weight;
 			    if (i == 0)
 			    {
+				if (new_curwin != NULL)
+				    new_curwin->w_arg_idx = opened_len;
 				new_curwin = wp;
 				new_curtab = curtab;
 			    }
 			}
-			if (wp->w_alist != curwin->w_alist)
+			else if (keep_tabs)
+			    i = opened_len;
+
+			if (wp->w_alist != alist)
 			{
 			    /* Use the current argument list for all windows
 			     * containing a file from it. */
 			    alist_unlink(wp->w_alist);
-			    wp->w_alist = curwin->w_alist;
+			    wp->w_alist = alist;
 			    ++wp->w_alist->al_refcount;
 			}
 			break;
@@ -4489,7 +4520,7 @@
 	    }
 	    wp->w_arg_idx = i;
 
-	    if (i == ARGCOUNT && !keep_tabs)	/* close this window */
+	    if (i == opened_len && !keep_tabs)/* close this window */
 	    {
 		if (P_HID(buf) || forceit || buf->b_nwindows > 1
 							|| !bufIsChanged(buf))
@@ -4511,7 +4542,8 @@
 		    }
 #ifdef FEAT_WINDOWS
 		    /* don't close last window */
-		    if (firstwin == lastwin && first_tabpage->tp_next == NULL)
+		    if (firstwin == lastwin
+			    && (first_tabpage->tp_next == NULL || !had_tab))
 #endif
 			use_firstwin = TRUE;
 #ifdef FEAT_WINDOWS
@@ -4545,20 +4577,16 @@
      * Open a window for files in the argument list that don't have one.
      * ARGCOUNT may change while doing this, because of autocommands.
      */
-    if (count > ARGCOUNT || count <= 0)
-	count = ARGCOUNT;
-
-    /* Autocommands may do anything to the argument list.  Make sure it's not
-     * freed while we are working here by "locking" it.  We still have to
-     * watch out for its size to be changed. */
-    alist = curwin->w_alist;
-    ++alist->al_refcount;
+    if (count > opened_len || count <= 0)
+	count = opened_len;
 
 #ifdef FEAT_AUTOCMD
     /* Don't execute Win/Buf Enter/Leave autocommands here. */
     ++autocmd_no_enter;
     ++autocmd_no_leave;
 #endif
+    last_curwin = curwin;
+    last_curtab = curtab;
     win_enter(lastwin, FALSE);
 #ifdef FEAT_WINDOWS
     /* ":drop all" should re-use an empty window to avoid "--remote-tab"
@@ -4568,11 +4596,11 @@
 	use_firstwin = TRUE;
 #endif
 
-    for (i = 0; i < count && i < alist->al_ga.ga_len && !got_int; ++i)
+    for (i = 0; i < count && i < opened_len && !got_int; ++i)
     {
 	if (alist == &global_alist && i == global_alist.al_ga.ga_len - 1)
 	    arg_had_last = TRUE;
-	if (i < opened_len && opened[i])
+	if (opened[i] > 0)
 	{
 	    /* Move the already present window to below the current window */
 	    if (curwin->w_arg_idx != i)
@@ -4581,7 +4609,13 @@
 		{
 		    if (wpnext->w_arg_idx == i)
 		    {
-			win_move_after(wpnext, curwin);
+			if (keep_tabs)
+			{
+			    new_curwin = wpnext;
+			    new_curtab = curtab;
+			}
+			else
+			    win_move_after(wpnext, curwin);
 			break;
 		    }
 		}
@@ -4636,6 +4670,14 @@
 #ifdef FEAT_AUTOCMD
     --autocmd_no_enter;
 #endif
+    /* restore last referenced tabpage's curwin */
+    if (last_curtab != new_curtab)
+    {
+	if (valid_tabpage(last_curtab))
+	    goto_tabpage_tp(last_curtab);
+	if (win_valid(last_curwin))
+	    win_enter(last_curwin, FALSE);
+    }
     /* to window with first arg */
     if (valid_tabpage(new_curtab))
 	goto_tabpage_tp(new_curtab);
diff --git a/src/testdir/test62.in b/src/testdir/test62.in
index b813830..c549c8b 100644
--- a/src/testdir/test62.in
+++ b/src/testdir/test62.in
@@ -50,6 +50,43 @@
 :call append(line('$'), test_status)
 :"
 :"
+:" Test for ":tab drop exist-file" to keep current window.
+:sp test1
+:tab drop test1
+:let test_status = 'tab drop 1: fail'
+:if tabpagenr('$') == 1 && winnr('$') == 2 && winnr() == 1
+:    let test_status = 'tab drop 1: pass'
+:endif
+:close
+:call append(line('$'), test_status)
+:"
+:"
+:" Test for ":tab drop new-file" to keep current window of tabpage 1.
+:split
+:tab drop newfile
+:let test_status = 'tab drop 2: fail'
+:if tabpagenr('$') == 2 && tabpagewinnr(1, '$') == 2 && tabpagewinnr(1) == 1
+:    let test_status = 'tab drop 2: pass'
+:endif
+:tabclose
+:q
+:call append(line('$'), test_status)
+:"
+:"
+:" Test for ":tab drop multi-opend-file" to keep current tabpage and window.
+:new test1
+:tabnew
+:new test1
+:tab drop test1
+:let test_status = 'tab drop 3: fail'
+:if tabpagenr() == 2 && tabpagewinnr(2, '$') == 2 && tabpagewinnr(2) == 1
+:    let test_status = 'tab drop 3: pass'
+:endif
+:tabclose
+:q
+:call append(line('$'), test_status)
+:"
+:"
 :/^Results/,$w! test.out
 :qa!
 ENDTEST
diff --git a/src/testdir/test62.ok b/src/testdir/test62.ok
index 9a51e44..7625cd2 100644
--- a/src/testdir/test62.ok
+++ b/src/testdir/test62.ok
@@ -5,3 +5,6 @@
 this is tab page 4
 gettabvar: pass
 settabvar: pass
+tab drop 1: pass
+tab drop 2: pass
+tab drop 3: pass
diff --git a/src/version.c b/src/version.c
index 7945ffe..f47e7bd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -715,6 +715,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    456,
+/**/
     455,
 /**/
     454,