patch 8.0.1133: syntax timeout not used correctly

Problem:    Syntax timeout not used correctly.
Solution:   Do not pass the timeout to syntax_start() but set it explicitly.
            (Yasuhiro Matsumoto, closes #2139)
diff --git a/src/screen.c b/src/screen.c
index 9f39edf..fb92416 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -131,7 +131,7 @@
 static void fill_foldcolumn(char_u *p, win_T *wp, int closed, linenr_T lnum);
 static void copy_text_attr(int off, char_u *buf, int len, int attr);
 #endif
-static int win_line(win_T *, linenr_T, int, int, int nochange, proftime_T *syntax_tm);
+static int win_line(win_T *, linenr_T, int, int, int nochange);
 static int char_needs_redraw(int off_from, int off_to, int cols);
 static void draw_vsep_win(win_T *wp, int row);
 #ifdef FEAT_STL_OPT
@@ -930,6 +930,7 @@
 #ifdef SYN_TIME_LIMIT
 	/* Set the time limit to 'redrawtime'. */
 	profile_setlimit(p_rdt, &syntax_tm);
+	syn_set_timeout(&syntax_tm);
 #endif
 	update_prepare();
 
@@ -944,13 +945,7 @@
 		start_search_hl();
 		prepare_search_hl(wp, lnum);
 # endif
-		win_line(wp, lnum, row, row + wp->w_lines[j].wl_size, FALSE,
-#ifdef SYN_TIME_LIMIT
-			&syntax_tm
-#else
-			NULL
-#endif
-			);
+		win_line(wp, lnum, row, row + wp->w_lines[j].wl_size, FALSE);
 # if defined(FEAT_SEARCH_EXTRA)
 		end_search_hl();
 # endif
@@ -960,6 +955,10 @@
 	}
 
 	update_finish();
+
+#ifdef SYN_TIME_LIMIT
+	syn_set_timeout(NULL);
+#endif
     }
     need_cursor_line_redraw = FALSE;
 }
@@ -1805,6 +1804,7 @@
 #ifdef SYN_TIME_LIMIT
     /* Set the time limit to 'redrawtime'. */
     profile_setlimit(p_rdt, &syntax_tm);
+    syn_set_timeout(&syntax_tm);
 #endif
 #ifdef FEAT_FOLDING
     win_foldinfo.fi_level = 0;
@@ -2109,13 +2109,7 @@
 		/*
 		 * Display one line.
 		 */
-		row = win_line(wp, lnum, srow, wp->w_height, mod_top == 0,
-#ifdef SYN_TIME_LIMIT
-			&syntax_tm
-#else
-			NULL
-#endif
-			);
+		row = win_line(wp, lnum, srow, wp->w_height, mod_top == 0);
 
 #ifdef FEAT_FOLDING
 		wp->w_lines[idx].wl_folded = FALSE;
@@ -2275,6 +2269,10 @@
 	win_draw_end(wp, '~', ' ', row, wp->w_height, HLF_EOB);
     }
 
+#ifdef SYN_TIME_LIMIT
+    syn_set_timeout(NULL);
+#endif
+
     /* Reset the type of redrawing required, the window has been updated. */
     wp->w_redr_type = 0;
 #ifdef FEAT_DIFF
@@ -3000,8 +2998,7 @@
     linenr_T	lnum,
     int		startrow,
     int		endrow,
-    int		nochange UNUSED,	/* not updating for changed text */
-    proftime_T	*syntax_tm UNUSED)
+    int		nochange UNUSED)	/* not updating for changed text */
 {
     int		col = 0;		/* visual column on screen */
     unsigned	off;			/* offset in ScreenLines/ScreenAttrs */
@@ -3216,7 +3213,7 @@
 	 * error, stop syntax highlighting. */
 	save_did_emsg = did_emsg;
 	did_emsg = FALSE;
-	syntax_start(wp, lnum, syntax_tm);
+	syntax_start(wp, lnum);
 	if (did_emsg)
 	    wp->w_s->b_syn_error = TRUE;
 	else
@@ -3614,7 +3611,7 @@
 # ifdef FEAT_SYN_HL
 	    /* Need to restart syntax highlighting for this line. */
 	    if (has_syntax)
-		syntax_start(wp, lnum, syntax_tm);
+		syntax_start(wp, lnum);
 # endif
 	}
 #endif