patch 7.4.834

Problem:    gettabvar() doesn't work after Vim start. (Szymon Wrozynski)
Solution:   Handle first window in tab still being NULL. (Christian Brabandt)

src/eval.c

@@ -12291,7 +12291,8 @@ f_gettabvar(argvars, rettv)
     {
 	/* Set tp to be our tabpage, temporarily.  Also set the window to the
 	 * first window in the tabpage, otherwise the window is not valid. */
-	if (switch_win(&oldcurwin, &oldtabpage, tp->tp_firstwin, tp, TRUE)
+	if (switch_win(&oldcurwin, &oldtabpage,
+		    tp->tp_firstwin == NULL ? firstwin : tp->tp_firstwin, tp, TRUE)
 									== OK)
 	{
 	    /* look up the variable */

src/testdir/test91.in

@@ -5,8 +5,12 @@ STARTTEST
 :so small.vim
 :so mbyte.vim
 :"
-:" Test for getbufvar()
 :" Use strings to test for memory leaks.
+:" First, check that in an empty window, gettabvar() returns the correct value
+:let t:testvar='abcd'
+:$put =string(gettabvar(1,'testvar'))
+:$put =string(gettabvar(1,'testvar'))
+:" Test for getbufvar()
 :let b:var_num = '1234'
 :let def_num = '5678'
 :$put =string(getbufvar(1, 'var_num'))

src/testdir/test91.ok

@@ -1,4 +1,6 @@
 start:
+'abcd'
+'abcd'
 '1234'
 '1234'
 {'var_num': '1234'}

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    834,
 /**/
     833,
 /**/