[5/6] gdb: Fix scrolling in TUI

diff --git a/gdb/testsuite/gdb.tui/basic.exp b/gdb/testsuite/gdb.tui/basic.exp
index c3a3fdd4f5e..be822f8a915 100644
--- a/gdb/testsuite/gdb.tui/basic.exp
+++ b/gdb/testsuite/gdb.tui/basic.exp
@@ -35,6 +35,19 @@  gdb_assert {![string match "No Source Available" $text]} \
 Term::command "list main"
 Term::check_contents "list main" "21 *return 0"
 
+# Get the first source line.
+set line [Term::get_line 1]
+# Send an up arrow.
+send_gdb "\033\[A"
+# Wait for a redraw and check that the first line changed.
+if {[Term::wait_for [string_to_regexp $line]] \
+	&& [Term::get_line 1] != $line\
+	&& [Term::get_line 2] == $line} {
+    pass "scroll up"
+} else {
+    fail "scroll up"
+}
+
 Term::check_box "source box" 0 0 80 15
 
 Term::command "layout asm"
diff --git a/gdb/testsuite/lib/tuiterm.exp b/gdb/testsuite/lib/tuiterm.exp
index 0307745d879..7adaf1b71ab 100644
--- a/gdb/testsuite/lib/tuiterm.exp
+++ b/gdb/testsuite/lib/tuiterm.exp
@@ -388,8 +388,10 @@  namespace eval Term {
 	_clear_lines 0 $_rows
     }
 
-    # Accept some output from gdb and update the screen.
-    proc _accept {wait_for} {
+    # Accept some output from gdb and update the screen.  WAIT_FOR is
+    # a regexp matching the line to wait for.  Return 0 on timeout, 1
+    # on success.
+    proc wait_for {wait_for} {
 	global expect_out
 	global gdb_prompt
 	variable _cur_x
@@ -424,7 +426,7 @@  namespace eval Term {
 		timeout {
 		    # Assume a timeout means we somehow missed the
 		    # expected result, and carry on.
-		    return
+		    return 0
 		}
 	    }
 
@@ -443,6 +445,8 @@  namespace eval Term {
 		set wait_for $prompt_wait_for
 	    }
 	}
+
+	return 1
     }
 
     # Like ::clean_restart, but ensures that gdb starts in an
@@ -490,7 +494,7 @@  namespace eval Term {
     # be supplied by this function.
     proc command {cmd} {
 	send_gdb "$cmd\n"
-	_accept [string_to_regexp $cmd]
+	wait_for [string_to_regexp $cmd]
     }
 
     # Return the text of screen line N, without attributes.  Lines are
@@ -682,14 +686,14 @@  namespace eval Term {
 	# Due to the strange column resizing behavior, and because we
 	# don't care about this intermediate resize, we don't check
 	# the size here.
-	_accept "@@ resize done $_resize_count"
+	wait_for "@@ resize done $_resize_count"
 	incr _resize_count
 	# Somehow the number of columns transmitted to gdb is one less
 	# than what we request from expect.  We hide this weird
 	# details from the caller.
 	_do_resize $_rows $cols
 	stty columns [expr {$_cols + 1}] < $gdb_spawn_name
-	_accept "@@ resize done $_resize_count, size = ${_cols}x${rows}"
+	wait_for "@@ resize done $_resize_count, size = ${_cols}x${rows}"
 	incr _resize_count
     }
 }
diff --git a/gdb/tui/tui-source.c b/gdb/tui/tui-source.c
index 1503cd4c636..13f2dc7cfe1 100644
--- a/gdb/tui/tui-source.c
+++ b/gdb/tui/tui-source.c
@@ -136,26 +136,29 @@  tui_source_window::do_scroll_vertical (int num_to_scroll)
 {
   if (!content.empty ())
     {
-      struct tui_line_or_address l;
       struct symtab *s;
       struct symtab_and_line cursal = get_current_source_symtab_and_line ();
+      struct gdbarch *arch = gdbarch;
 
       if (cursal.symtab == NULL)
-	s = find_pc_line_symtab (get_frame_pc (get_selected_frame (NULL)));
+	{
+	  struct frame_info *fi = get_selected_frame (NULL);
+	  s = find_pc_line_symtab (get_frame_pc (fi));
+	  arch = get_frame_arch (fi);
+	}
       else
 	s = cursal.symtab;
 
-      l.loa = LOA_LINE;
-      l.u.line_no = start_line_or_addr.u.line_no
-	+ num_to_scroll;
+      int line_no = start_line_or_addr.u.line_no + num_to_scroll;
       const std::vector<off_t> *offsets;
       if (g_source_cache.get_line_charpos (s, &offsets)
-	  && l.u.line_no > offsets->size ())
-	l.u.line_no = start_line_or_addr.u.line_no;
-      if (l.u.line_no <= 0)
-	l.u.line_no = 1;
+	  && line_no > offsets->size ())
+	line_no = start_line_or_addr.u.line_no;
+      if (line_no <= 0)
+	line_no = 1;
 
-      print_source_lines (s, l.u.line_no, l.u.line_no + 1, 0);
+      cursal.line = line_no;
+      update_source_window (arch, cursal);
     }
 }