patch 8.2.0648: semicolon search does not work in first line

Problem:    Semicolon search does not work in first line.
Solution:   Allow the cursor to be in line zero. (Christian Brabandt,
            closes #5996)

src/ex_docmd.c

@@ -3069,8 +3069,10 @@ parse_cmd_address(exarg_T *eap, char **errormsg, int silent)
 	    if (!eap->skip)
 	    {
 		curwin->w_cursor.lnum = eap->line2;
-		// don't leave the cursor on an illegal line or column
+		// Don't leave the cursor on an illegal line or column, but do
-		check_cursor();
+		// accept zero as address, so 0;/PATTERN/ works correctly.
+		if (eap->line2 > 0)
+		    check_cursor();
 	    }
 	}
 	else if (*eap->cmd != ',')

src/testdir/test_cmdline.vim

@@ -1471,4 +1471,15 @@ func Test_cmdwin_insert_mode_close()
   call assert_equal(1, winnr('$'))
 endfunc
 
+" test that ";" works to find a match at the start of the first line
+func Test_zero_line_search()
+  new
+  call setline(1, ["1, pattern", "2, ", "3, pattern"])
+  call cursor(1,1)
+  0;/pattern/d
+  call assert_equal(["2, ", "3, pattern"], getline(1,'$'))
+  q!
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    648,
 /**/
     647,
 /**/