patch 8.0.1151: "vim -c startinsert!" doesn't append

Problem:    "vim -c startinsert!" doesn't append.
Solution:   Correct line number on startup. (Christian Brabandt, closes #2117)

Author: brammool

src/ex_docmd.c

@@ -10294,6 +10294,9 @@ ex_startinsert(exarg_T *eap)
 {
     if (eap->forceit)
     {
+	/* cursor line can be zero on startup */
+	if (!curwin->w_cursor.lnum)
+	    curwin->w_cursor.lnum = 1;
 	coladvance((colnr_T)MAXCOL);
 	curwin->w_curswant = MAXCOL;
 	curwin->w_set_curswant = FALSE;

src/testdir/test_startup.vim

@@ -263,3 +263,27 @@ func Test_default_term()
   call assert_match("defaulting to 'ansi'", out)
   let $TERM = save_term
 endfunc
+
+func Test_zzz_startinsert()
+  " Test :startinsert
+  call writefile(['123456'], 'Xtestout')
+  let after = [
+	\ ':startinsert',
+  \ 'call feedkeys("foobar\<c-o>:wq\<cr>","t")'
+	\ ]
+  if RunVim([], after, 'Xtestout')
+    let lines = readfile('Xtestout')
+    call assert_equal(['foobar123456'], lines)
+  endif
+  " Test :startinsert!
+  call writefile(['123456'], 'Xtestout')
+  let after = [
+	\ ':startinsert!',
+  \ 'call feedkeys("foobar\<c-o>:wq\<cr>","t")'
+	\ ]
+  if RunVim([], after, 'Xtestout')
+    let lines = readfile('Xtestout')
+    call assert_equal(['123456foobar'], lines)
+  endif
+  call delete('Xtestout')
+endfunc

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1151,
 /**/
     1150,
 /**/