updated for version 7.3.591

Problem:    Can only move to a tab by absolute number.
Solution:   Move a number of tabs to the left or the right. (Lech Lorens)

runtime/doc/tabpage.txt

@@ -173,10 +173,20 @@ Other commands:
 REORDERING TAB PAGES:
 
 :tabm[ove] [N]						*:tabm* *:tabmove*
+:[N]tabm[ove]
 		Move the current tab page to after tab page N.  Use zero to
 		make the current tab page the first one.  Without N the tab
 		page is made the last one.
 
+:tabm[ove] +[N]
+:tabm[ove] -[N]
+		Move the current tab page N places to the right (with +) or to
+		the left (with -).
+
+Note that although it is possible to move a tab behind the N-th one by using
+:Ntabmove, it is impossible to move it by N places by using :+Ntabmove. For
+clarification what +N means in this context see |[range]|.
+
 
 LOOPING OVER TAB PAGES:
 

src/ex_cmds.h

@@ -944,7 +944,7 @@ EX(CMD_tabfind,		"tabfind",	ex_splitview,
 EX(CMD_tabfirst,	"tabfirst",	ex_tabnext,
 			TRLBAR),
 EX(CMD_tabmove,		"tabmove",	ex_tabmove,
-			RANGE|NOTADR|ZEROR|COUNT|TRLBAR|ZEROR),
+			RANGE|NOTADR|ZEROR|EXTRA|NOSPC|TRLBAR),
 EX(CMD_tablast,		"tablast",	ex_tabnext,
 			TRLBAR),
 EX(CMD_tabnext,		"tabnext",	ex_tabnext,

src/ex_docmd.c

@@ -7478,7 +7478,42 @@ ex_tabnext(eap)
 ex_tabmove(eap)
     exarg_T	*eap;
 {
-    tabpage_move(eap->addr_count == 0 ? 9999 : (int)eap->line2);
+    int tab_number = 9999;
+
+    if (eap->arg && *eap->arg != NUL)
+    {
+	char_u *p = eap->arg;
+	int    relative = 0; /* argument +N/-N means: move N places to the
+			      * right/left relative to the current position. */
+
+	if (*eap->arg == '-')
+	{
+	    relative = -1;
+	    p = eap->arg + 1;
+	}
+	else if (*eap->arg == '+')
+	{
+	    relative = 1;
+	    p = eap->arg + 1;
+	}
+	else
+	    p = eap->arg;
+
+	if (p == skipdigits(p))
+	{
+	    /* No numbers as argument. */
+	    eap->errmsg = e_invarg;
+	    return;
+	}
+
+	tab_number = getdigits(&p);
+	if (relative != 0)
+	    tab_number = tab_number * relative + tabpage_index(curtab) - 1;;
+    }
+    else if (eap->addr_count != 0)
+	tab_number = eap->line2;
+
+    tabpage_move(tab_number);
 }
 
 /*

src/testdir/test62.in

@@ -93,6 +93,34 @@ STARTTEST
 :endif
 :"
 :"
+:for i in range(9) | tabnew | endfor
+1gt
+Go=tabpagenr()


+:tabmove 5
+i=tabpagenr()


+:tabmove -2
+i=tabpagenr()


+:tabmove +4
+i=tabpagenr()


+:tabmove
+i=tabpagenr()


+:tabmove -20
+i=tabpagenr()


+:tabmove +20
+i=tabpagenr()


+:3tabmove
+i=tabpagenr()


+:7tabmove 5
+i=tabpagenr()


+:let a='No error caught.'
+:try
+:tabmove foo
+:catch E474
+:let a='E474 caught.'
+:endtry
+i=a

+:"
+:"
 :/^Results/,$w! test.out
 :qa!
 ENDTEST

src/testdir/test62.ok

@@ -8,3 +8,13 @@ settabvar: pass
 tab drop 1: pass
 tab drop 2: pass
 tab drop 3: pass
+1
+6
+4
+8
+10
+1
+10
+4
+6
+E474 caught.

src/version.c

@@ -714,6 +714,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    591,
 /**/
     590,
 /**/

src/window.c

@@ -3929,7 +3929,7 @@ tabpage_move(nr)
     }
 
     /* Re-insert it at the specified position. */
-    if (n == 0)
+    if (n <= 0)
     {
 	curtab->tp_next = first_tabpage;
 	first_tabpage = curtab;