[gdb/tui] Fix wrapping strings

I noticed that after resizing to a narrow window, I got:
...
┌────────────────┐
│                │
│[ No Source Avail
able ]           │
│                │
└────────────────┘
...

Fix this by adding two new functions:
- tui_win_info::display_string (int y, int x, const char *str)
- tui_win_info::display_string (const char *str)
that make sure that borders are not overwritten, which get us instead:
...
┌────────────────┐
│                │
│[ No Source Avai│
│                │
│                │
└────────────────┘
...

Tested on x86_64-linux.

5 files changed, 42 insertions, 7 deletions

diff --git a/gdb/tui/tui-data.c b/gdb/tui/tui-data.c
index fc90df2..c51bd11 100644
--- a/gdb/tui/tui-data.c
+++ b/gdb/tui/tui-data.c
@@ -164,6 +164,36 @@ tui_win_info::set_title (std::string &&new_title)
     }
 }
 
+/* See tui-data.h.  */
+
+void
+tui_win_info::display_string (int y, int x, const char *str) const
+{
+  int n = width - box_width () - x;
+  if (n <= 0)
+    return;
+
+  mvwaddnstr (handle.get (), y, x, str, n);
+}
+
+/* See tui-data.h.  */
+
+void
+tui_win_info::display_string (const char *str) const
+{
+  int y, x;
+  getyx (handle.get (), y, x);
+
+  /* Avoid Wunused-but-set-variable.  */
+  (void) y;
+
+  int n = width - box_width () - x;
+  if (n <= 0)
+    return;
+
+  waddnstr (handle.get (), str, n);
+}
+
 void
 tui_win_info::rerender ()
 {
diff --git a/gdb/tui/tui-data.h b/gdb/tui/tui-data.h
index 82340e5..76d0de3 100644
--- a/gdb/tui/tui-data.h
+++ b/gdb/tui/tui-data.h
@@ -167,6 +167,14 @@ public:
   const std::string &title () const
   { return m_title; }
 
+  /* Display string STR in the window at position (Y,X), abbreviated if
+     necessary.  */
+  void display_string (int y, int x, const char *str) const;
+
+  /* Display string STR in the window at the current cursor position,
+     abbreviated if necessary.  */
+  void display_string (const char *str) const;
+
   /* Window handle.  */
   std::unique_ptr<WINDOW, curses_deleter> handle;
   /* Window width.  */
diff --git a/gdb/tui/tui-regs.c b/gdb/tui/tui-regs.c
index 01538d4..4c6ea8a 100644
--- a/gdb/tui/tui-regs.c
+++ b/gdb/tui/tui-regs.c
@@ -407,7 +407,7 @@ tui_data_window::erase_data_content (const char *prompt)
 	x_pos = 1;
       else
 	x_pos = half_width - strlen (prompt);
-      mvwaddstr (handle.get (), (height / 2), x_pos, (char *) prompt);
+      display_string (height / 2, x_pos, prompt);
     }
   tui_wrefresh (handle.get ());
 }
diff --git a/gdb/tui/tui-source.c b/gdb/tui/tui-source.c
index 5e9a954..bce381a 100644
--- a/gdb/tui/tui-source.c
+++ b/gdb/tui/tui-source.c
@@ -253,5 +253,5 @@ tui_source_window::show_line_number (int offset) const
 		 tui_left_margin_verbose ? "%0*d%c" : "%*d%c", m_digits - 1,
 		 lineno, space);
     }
-  waddstr (handle.get (), text);
+  display_string (text);
 }
diff --git a/gdb/tui/tui-winsource.c b/gdb/tui/tui-winsource.c
index ea4ca21..acbaef9 100644
--- a/gdb/tui/tui-winsource.c
+++ b/gdb/tui/tui-winsource.c
@@ -223,10 +223,7 @@ tui_source_window_base::do_erase_source_content (const char *str)
 	x_pos = 1;
       else
 	x_pos = half_width - strlen (str);
-      mvwaddstr (handle.get (),
-		 (height / 2),
-		 x_pos,
-		 (char *) str);
+      display_string (height / 2, x_pos, str);
 
       refresh_window ();
     }
@@ -697,7 +694,7 @@ tui_source_window_base::update_exec_info (bool refresh_p)
       if (src_element->is_exec_point)
 	element[TUI_EXEC_POS] = '>';
 
-      mvwaddstr (handle.get (), i + box_width (), box_width (), element);
+      display_string (i + box_width (), box_width (), element);
 
       show_line_number (i);
     }