diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 13024ce6df9b..bf0031230c9e 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2019-03-16  Eli Zaretskii  <eliz@gnu.org>
+
+	* source-cache.c (source_cache::get_source_lines): Call
+	find_source_lines to initialize s->nlines.  This fixes vertical
+	scrolling of TUI source window when the DOWN arrow is pressed.
+
 2019-03-16  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
 
 	* auto-load.c (_initialize_auto_load): Fix 'This options has'.
diff --git a/gdb/source-cache.c b/gdb/source-cache.c
index 1ed2601c6145..9211f098eb70 100644
--- a/gdb/source-cache.c
+++ b/gdb/source-cache.c
@@ -200,6 +200,13 @@ source_cache::get_source_lines (struct symtab *s, int first_line,
 	  std::ifstream input (fullname);
 	  if (input.is_open ())
 	    {
+	      if (s->line_charpos == 0)
+		{
+		  scoped_fd desc = open_source_file (s);
+		  if (desc.get () < 0)
+		    return false;
+		  find_source_lines (s, desc.get ());
+		}
 	      srchilite::SourceHighlight highlighter ("esc.outlang");
 	      highlighter.setStyleFile("esc.style");