Remove unnecessary system includes from public headers

Add includes of system headers in the implementation files
where necessary.

35 files changed, 73 insertions, 75 deletions

diff --git a/FL/Fl.H b/FL/Fl.H
index dfa9c5748..1706cc2d5 100644
--- a/FL/Fl.H
+++ b/FL/Fl.H
@@ -42,6 +42,7 @@
 #    undef BSD
 #  endif
 
+#include <string.h> // FIXME: Fl::is_scheme(): strcmp needs string.h
 
 class Fl_Widget;
 class Fl_Window;
diff --git a/FL/Fl_Device.H b/FL/Fl_Device.H
index f7ec44052..9615bdc44 100644
--- a/FL/Fl_Device.H
+++ b/FL/Fl_Device.H
@@ -2,7 +2,7 @@
 // Definition of classes Fl_Surface_Device, Fl_Display_Device
 // for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2017 by Bill Spitzak and others.
+// Copyright 2010-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -24,7 +24,6 @@
 
 #include <FL/Fl_Plugin.H>
 #include <FL/platform_types.h>
-#include <stdlib.h>
 
 class Fl_Graphics_Driver;
 class Fl_RGB_Image;
diff --git a/FL/Fl_File_Chooser.H b/FL/Fl_File_Chooser.H
index 341b8e683..5935edc28 100644
--- a/FL/Fl_File_Chooser.H
+++ b/FL/Fl_File_Chooser.H
@@ -1,7 +1,7 @@
 //
 // Fl_File_Chooser dialog for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2015 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -27,9 +27,6 @@
 #define Fl_File_Chooser_H
 #include <FL/Fl.H>
 #include <FL/Fl_Double_Window.H>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <FL/Fl_Group.H>
 #include <FL/Fl_Choice.H>
 #include <FL/Fl_Menu_Button.H>
diff --git a/FL/Fl_Graphics_Driver.H b/FL/Fl_Graphics_Driver.H
index 974f1be3c..9d2b85f26 100644
--- a/FL/Fl_Graphics_Driver.H
+++ b/FL/Fl_Graphics_Driver.H
@@ -33,7 +33,6 @@
 #include <FL/Fl_Bitmap.H>
 #include <FL/Fl_Pixmap.H>
 #include <FL/Fl_RGB_Image.H>
-#include <stdlib.h>
 
 class Fl_Graphics_Driver;
 class Fl_Font_Descriptor;
diff --git a/FL/Fl_Help_Dialog.H b/FL/Fl_Help_Dialog.H
index ef5f31028..ed19ca2a2 100644
--- a/FL/Fl_Help_Dialog.H
+++ b/FL/Fl_Help_Dialog.H
@@ -1,7 +1,7 @@
 //
 // Fl_Help_Dialog dialog for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2015 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
diff --git a/FL/Fl_Image.H b/FL/Fl_Image.H
index daac00165..f39e0eaeb 100644
--- a/FL/Fl_Image.H
+++ b/FL/Fl_Image.H
@@ -21,7 +21,6 @@
 #define Fl_Image_H
 
 #include "Enumerations.H"
-#include <stdlib.h>
 #include "Fl_Widget.H" // for fl_uintptr_t
 
 class Fl_Widget;
diff --git a/FL/Fl_Input_Choice.H b/FL/Fl_Input_Choice.H
index 9f29ce968..71bc76ee0 100644
--- a/FL/Fl_Input_Choice.H
+++ b/FL/Fl_Input_Choice.H
@@ -5,8 +5,8 @@
 //           | input area   || \/ |
 //           |______________||____|
 //
-// Copyright 1998-2017 by Bill Spitzak and others.
 // Copyright 2004 by Greg Ercolano.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -30,13 +30,6 @@
 #include <FL/Fl_Input.H>
 #include <FL/Fl_Menu_Button.H>
 
-// Leaving these two headers so builds don't break if user includes this
-// header and uses items from fl_draw or string (but doesn't include in src).
-// Note: this would ensure compatibility with FLTK 1.3.x.
-// Shall we? Currently not!
-// #include <FL/fl_draw.H>
-// #include <string.h>
-
 /*
   A combination of the input widget and a menu button.
 
diff --git a/FL/Fl_Text_Buffer.H b/FL/Fl_Text_Buffer.H
index 473e61c77..a1d044f48 100644
--- a/FL/Fl_Text_Buffer.H
+++ b/FL/Fl_Text_Buffer.H
@@ -1,7 +1,7 @@
 //
 // Header file for Fl_Text_Buffer class.
 //
-// Copyright 2001-2017 by Bill Spitzak and others.
+// Copyright 2001-2021 by Bill Spitzak and others.
 // Original code Copyright Mark Edel.  Permission to distribute under
 // the LGPL for the FLTK library granted by Mark Edel.
 //
@@ -22,7 +22,7 @@
 #ifndef FL_TEXT_BUFFER_H
 #define FL_TEXT_BUFFER_H
 
-#include <stdarg.h>     /* va_start/end */
+#include <stdarg.h>     /* va_list */
 
 #undef ASSERT_UTF8
 
diff --git a/FL/Fl_Window.H b/FL/Fl_Window.H
index 9c83d7b11..4ce65f3bc 100644
--- a/FL/Fl_Window.H
+++ b/FL/Fl_Window.H
@@ -23,7 +23,6 @@
 #include <FL/Fl.H>
 #include <FL/Fl_Group.H>
 #include <FL/Fl_Bitmap.H>
-#include <stdlib.h>
 
 #define FL_WINDOW 0xF0          ///< window type id: all subclasses have type() >= this
 #define FL_DOUBLE_WINDOW 0xF1   ///< double window type id
diff --git a/FL/fl_utf8.h b/FL/fl_utf8.h
index 8cf26900a..315f24cf6 100644
--- a/FL/fl_utf8.h
+++ b/FL/fl_utf8.h
@@ -29,9 +29,7 @@
 
 #include "Fl_Export.H"
 #include "fl_types.h"
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
+#include <stdio.h>   // FILE *fl_fopen()
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/examples/OpenGL3-glut-test.cxx b/examples/OpenGL3-glut-test.cxx
index 81a22c211..75ff3b0d1 100644
--- a/examples/OpenGL3-glut-test.cxx
+++ b/examples/OpenGL3-glut-test.cxx
@@ -1,7 +1,7 @@
 //
 // Tiny OpenGL v3 + glut demo program for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2015 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -14,7 +14,6 @@
 //     https://www.fltk.org/bugs.php
 //
 
-#include <stdio.h>
 #if defined(__APPLE__)
 #  define GL_DO_NOT_WARN_IF_MULTI_GL_VERSION_HEADERS_INCLUDED 1
 #  include <OpenGL/gl3.h> // defines OpenGL 3.0+ functions
@@ -25,7 +24,8 @@
 #  include <GL/glew.h>
 #endif
 #include <FL/glut.H>
-
+#include <stdio.h>
+#include <stdlib.h>
 
 // Globals
 // Real programs don't use globals :-D
diff --git a/fluid/ExternalCodeEditor_WIN32.cxx b/fluid/ExternalCodeEditor_WIN32.cxx
index b05adc638..695578749 100644
--- a/fluid/ExternalCodeEditor_WIN32.cxx
+++ b/fluid/ExternalCodeEditor_WIN32.cxx
@@ -3,8 +3,6 @@
 //
 //      Note: This entire file Windows only.
 
-#include <stdio.h>      // snprintf()
-
 #include <FL/Fl.H>      // Fl_Timeout_Handler..
 #include <FL/fl_ask.H>  // fl_alert()
 #include <FL/fl_utf8.h> // fl_utf8fromwc()
@@ -12,6 +10,9 @@
 
 #include "ExternalCodeEditor_WIN32.h"
 
+#include <stdio.h>      // snprintf()
+#include <stdlib.h>
+
 extern int G_debug;     // defined in fluid.cxx
 
 // Static local data
diff --git a/fluid/Fl_Type.h b/fluid/Fl_Type.h
index 7b008f092..a6e030674 100644
--- a/fluid/Fl_Type.h
+++ b/fluid/Fl_Type.h
@@ -29,6 +29,7 @@
 #include "Fluid_Image.h"
 #include <FL/fl_draw.H>
 #include <stdarg.h>
+#include <stdlib.h>
 
 #ifdef _WIN32
   #include "ExternalCodeEditor_WIN32.h"
diff --git a/fluid/Fluid_Image.cxx b/fluid/Fluid_Image.cxx
index 1f41a09fd..ba44175f3 100644
--- a/fluid/Fluid_Image.cxx
+++ b/fluid/Fluid_Image.cxx
@@ -16,6 +16,9 @@
 
 #include <FL/Fl.H>
 #include <FL/Fl_Widget.H>
+#include <FL/filename.H>
+#include <FL/fl_string.h>
+#include <FL/fl_utf8.h>     // fl_fopen()
 #include "Fl_Type.h"
 #include "Fluid_Image.h"
 #include "../src/flstring.h"
@@ -23,8 +26,6 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <stdarg.h>
-#include <FL/filename.H>
-#include <FL/fl_string.h>
 
 extern void goto_source_dir(); // in fluid.cxx
 extern void leave_source_dir(); // in fluid.cxx
diff --git a/src/Fl_File_Chooser.cxx b/src/Fl_File_Chooser.cxx
index 22fadf57f..b2993633d 100644
--- a/src/Fl_File_Chooser.cxx
+++ b/src/Fl_File_Chooser.cxx
@@ -1,7 +1,7 @@
 //
 // Fl_File_Chooser dialog for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2015 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
diff --git a/src/Fl_File_Chooser.fl b/src/Fl_File_Chooser.fl
index 62009f89d..7bffa6411 100644
--- a/src/Fl_File_Chooser.fl
+++ b/src/Fl_File_Chooser.fl
@@ -5,7 +5,7 @@ code_name {.cxx}
 comment {//
 // Fl_File_Chooser dialog for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2015 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -77,12 +77,9 @@ class FL_EXPORT Fl_File_Chooser {open
       callback {fileName->value("");
 fileList->deselect();
 Fl::remove_timeout((Fl_Timeout_Handler)previewCB, this);
-window->hide();} open
+window->hide();} open selected
       private xywh {1171 438 490 380} type Double hide resizable
-      code0 {if (title) window->label(title);}
-      code1 {\#include <stdio.h>}
-      code2 {\#include <stdlib.h>}
-      code3 {\#include <string.h>} modal
+      code0 {if (title) window->label(title);} modal
     } {
       Fl_Group {} {open
         private xywh {10 10 470 25}
@@ -116,7 +113,7 @@ window->hide();} open
           code0 {\#include <FL/Fl_File_Browser.H>}
         }
         Fl_Box errorBox {
-          label {dynamic error display} selected
+          label {dynamic error display}
           private xywh {10 45 295 225} box DOWN_BOX color 7 labelsize 18 labelcolor 1 align 149 hide
         }
         Fl_Box previewBox {
diff --git a/src/Fl_Gl_Choice.cxx b/src/Fl_Gl_Choice.cxx
index 6b718fcfd..f0ddda652 100644
--- a/src/Fl_Gl_Choice.cxx
+++ b/src/Fl_Gl_Choice.cxx
@@ -1,7 +1,7 @@
 //
 // OpenGL visual selection code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -22,11 +22,12 @@
  \addtogroup DriverDeveloper
  \{
  */
-#  include <FL/Fl.H>
-#  include "Fl_Gl_Choice.H"
-#  include <FL/Fl_Gl_Window.H>
-#  include "Fl_Gl_Window_Driver.H"
-#  include <FL/gl_draw.H>
+#include <FL/Fl.H>
+#include "Fl_Gl_Choice.H"
+#include <FL/Fl_Gl_Window.H>
+#include "Fl_Gl_Window_Driver.H"
+#include <FL/gl_draw.H>
+#include <stdlib.h>
 
 GLContext *Fl_Gl_Window_Driver::context_list = 0;
 int Fl_Gl_Window_Driver::nContext = 0;
diff --git a/src/Fl_Graphics_Driver.cxx b/src/Fl_Graphics_Driver.cxx
index 5386d5290..3ac4d3154 100644
--- a/src/Fl_Graphics_Driver.cxx
+++ b/src/Fl_Graphics_Driver.cxx
@@ -1,7 +1,7 @@
 //
 // Fl_Graphics_Driver class for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2020 by Bill Spitzak and others.
+// Copyright 2010-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -29,6 +29,7 @@
 #include <FL/Fl_Image_Surface.H>
 #include <FL/math.h>
 #include <FL/platform.H>
+#include <stdlib.h>
 
 FL_EXPORT Fl_Graphics_Driver *fl_graphics_driver; // the current driver of graphics operations
 
diff --git a/src/Fl_Help_Dialog.cxx b/src/Fl_Help_Dialog.cxx
index 580812818..54bbee1c2 100644
--- a/src/Fl_Help_Dialog.cxx
+++ b/src/Fl_Help_Dialog.cxx
@@ -1,7 +1,7 @@
 //
 // Fl_Help_Dialog dialog for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2015 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
diff --git a/src/Fl_Help_Dialog.fl b/src/Fl_Help_Dialog.fl
index 08ceef804..6aeb12e94 100644
--- a/src/Fl_Help_Dialog.fl
+++ b/src/Fl_Help_Dialog.fl
@@ -5,7 +5,7 @@ code_name {.cxx}
 comment {//
 // Fl_Help_Dialog dialog for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2015 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
diff --git a/src/Fl_Image_Surface.cxx b/src/Fl_Image_Surface.cxx
index e273a4c2f..e2870e578 100644
--- a/src/Fl_Image_Surface.cxx
+++ b/src/Fl_Image_Surface.cxx
@@ -1,7 +1,7 @@
 //
 // Draw-to-image code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2017 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -18,6 +18,8 @@
 
 #include <FL/fl_draw.H> // necessary for FL_EXPORT fl_*_offscreen()
 
+#include <stdlib.h>     // realloc()
+
 /** Constructor with optional high resolution.
  \param w,h Width and height of the resulting image. The value of the \p high_res
  parameter controls whether \p w and \p h are interpreted as pixels or FLTK units.
diff --git a/src/Fl_Table_Row.cxx b/src/Fl_Table_Row.cxx
index 33a1e4dd4..29d77747e 100644
--- a/src/Fl_Table_Row.cxx
+++ b/src/Fl_Table_Row.cxx
@@ -25,6 +25,7 @@
 #include <FL/Fl_Table_Row.H>
 #include <FL/Fl.H>
 #include <FL/fl_draw.H>
+#include <stdlib.h>
 
 // for debugging...
 // #define DEBUG 1
diff --git a/src/Fl_Tabs.cxx b/src/Fl_Tabs.cxx
index 17b73fdc9..4c83b6476 100644
--- a/src/Fl_Tabs.cxx
+++ b/src/Fl_Tabs.cxx
@@ -1,7 +1,7 @@
 //
 // Tab widget for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -20,12 +20,14 @@
 // Each child widget is a card, and its label() is printed on the card tab.
 // Clicking the tab makes that card visible.
 
-#include <stdio.h>
 #include <FL/Fl.H>
 #include <FL/Fl_Tabs.H>
 #include <FL/fl_draw.H>
 #include <FL/Fl_Tooltip.H>
 
+#include <stdio.h>
+#include <stdlib.h>
+
 #define BORDER 2
 #define EXTRASPACE 10
 #define SELECTION_BORDER 5
diff --git a/src/Fl_Tile.cxx b/src/Fl_Tile.cxx
index 997c6dd2d..9b42d5f69 100644
--- a/src/Fl_Tile.cxx
+++ b/src/Fl_Tile.cxx
@@ -85,6 +85,7 @@
 #include <FL/Fl_Tile.H>
 #include <FL/Fl_Window.H>
 #include <FL/Fl_Rect.H>
+#include <stdlib.h>
 
 /**
   Drags the intersection at (\p oldx,\p oldy) to (\p newx,\p newy).
diff --git a/src/drivers/GDI/Fl_GDI_Graphics_Driver.H b/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
index cf8ae3e98..9016e9f5a 100644
--- a/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
+++ b/src/drivers/GDI/Fl_GDI_Graphics_Driver.H
@@ -2,7 +2,7 @@
 // Definition of classes  Fl_Graphics_Driver, Fl_Surface_Device, Fl_Display_Device
 // for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2018 by Bill Spitzak and others.
+// Copyright 2010-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -25,7 +25,7 @@
 
 #include <FL/Fl_Graphics_Driver.H>
 #include <windows.h>
-
+#include <stdlib.h>
 
 /**
   \brief The Windows-specific graphics driver class.
diff --git a/src/drivers/SVG/Fl_SVG_File_Surface.cxx b/src/drivers/SVG/Fl_SVG_File_Surface.cxx
index 08727c842..371e618e1 100644
--- a/src/drivers/SVG/Fl_SVG_File_Surface.cxx
+++ b/src/drivers/SVG/Fl_SVG_File_Surface.cxx
@@ -29,6 +29,7 @@
 #include <FL/Fl_Pixmap.H>
 #include <FL/Fl_Bitmap.H>
 #include <FL/fl_string.h>
+#include <stdlib.h>
 
 extern "C" {
 #if defined(HAVE_LIBPNG)
diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx
index 6401efa97..a96682554 100644
--- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx
+++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx
@@ -22,6 +22,7 @@
 #include <FL/platform.H>
 
 #include <string.h>
+#include <stdlib.h>
 
 extern XIC fl_xim_ic;
 extern char fl_is_over_the_spot;
diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_line_style.cxx b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_line_style.cxx
index 1aaeceea1..17fbba7fa 100644
--- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_line_style.cxx
+++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_line_style.cxx
@@ -1,7 +1,7 @@
 //
 // Line style code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -23,8 +23,8 @@
 #include <FL/fl_draw.H>
 #include <FL/platform.H>
 #include "../../flstring.h"
-
 #include "Fl_Xlib_Graphics_Driver.H"
+#include <stdlib.h>
 
 void Fl_Xlib_Graphics_Driver::line_style_unscaled(int style, int width, char* dashes) {
 
diff --git a/src/fl_ask.cxx b/src/fl_ask.cxx
index f711a9f1d..c9255f14e 100644
--- a/src/fl_ask.cxx
+++ b/src/fl_ask.cxx
@@ -1,7 +1,7 @@
 //
 // Standard dialog functions for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2020 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -24,14 +24,10 @@
 // mostly.  In most cases it is easier to get a multi-line message
 // by putting newlines in the message.
 
-#include <stdio.h>
-#include <stdarg.h>
-#include "flstring.h"
-
 #include <FL/Fl.H>
 #include <FL/fl_string.h>
-
 #include <FL/fl_ask.H>
+#include "flstring.h"
 
 #include <FL/Fl_Box.H>
 #include <FL/Fl_Button.H>
@@ -43,6 +39,10 @@
 #include "Fl_Screen_Driver.H"
 #include <FL/fl_draw.H>
 
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdlib.h>
+
 static Fl_Window *message_form;
 static Fl_Box *message;
 static Fl_Box *icon;
diff --git a/src/fl_draw.cxx b/src/fl_draw.cxx
index 16906366d..ba33db96e 100644
--- a/src/fl_draw.cxx
+++ b/src/fl_draw.cxx
@@ -30,7 +30,7 @@
 #include "flstring.h"
 #include <ctype.h>
 #include <math.h>
-
+#include <stdlib.h>
 
 char fl_draw_shortcut;  // set by fl_labeltypes.cxx
 
diff --git a/src/gl_draw.cxx b/src/gl_draw.cxx
index 048510266..f802376cb 100644
--- a/src/gl_draw.cxx
+++ b/src/gl_draw.cxx
@@ -1,7 +1,7 @@
 //
 // OpenGL text drawing support routines for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -42,6 +42,7 @@
 #include <FL/Fl_Image_Surface.H>
 #include <FL/glu.h>  // for gluUnProject()
 #include <FL/glut.H> // for glutStrokeString() and glutStrokeLength()
+#include <stdlib.h>
 
 #ifndef GL_TEXTURE_RECTANGLE_ARB
 #  define GL_TEXTURE_RECTANGLE_ARB 0x84F5
diff --git a/src/makedepend b/src/makedepend
index 7a511e043..ee601e022 100644
--- a/src/makedepend
+++ b/src/makedepend
@@ -1,5 +1,6 @@
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
+drivers/Cairo/Fl_Cairo_Graphics_Driver.o: ../config.h
 drivers/OpenGL/Fl_OpenGL_Display_Device.o: ../config.h
 drivers/OpenGL/Fl_OpenGL_Display_Device.o: ../FL/abi-version.h
 drivers/OpenGL/Fl_OpenGL_Display_Device.o: ../FL/Enumerations.H
diff --git a/test/file_chooser.cxx b/test/file_chooser.cxx
index abd5a081e..b705f052e 100644
--- a/test/file_chooser.cxx
+++ b/test/file_chooser.cxx
@@ -2,7 +2,7 @@
 // File chooser test program.
 //
 // Copyright 1999-2010 by Michael Sweet.
-// Copyright 2011-2019 by Bill Spitzak and others.
+// Copyright 2011-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -30,7 +30,6 @@
 // Include necessary headers...
 //
 
-#include <stdio.h>
 #include <FL/Fl_File_Chooser.H>
 #include <FL/Fl_File_Icon.H>
 #include <FL/Fl_Shared_Image.H>
@@ -38,7 +37,10 @@
 #include <FL/Fl_Light_Button.H>
 #include <FL/Fl_Double_Window.H>
 #include <FL/Fl_Simple_Terminal.H>
+
+#include <stdio.h>
 #include <string.h>
+#include <stdlib.h>     // exit()
 #include <locale.h>     // setlocale()..
 
 #define TERMINAL_HEIGHT 120
@@ -300,7 +302,7 @@ pdf_check(const char *name,     // I - Name of file
           "-sstdout=\"%%stderr\" -sOUTPUTFILE=\'%s\' "
           "-dFirstPage=1 -dLastPage=1 \'%s\' 2>/dev/null", preview, name);
 
-  if (system(command)) return 0;
+  if (fl_system(command)) return 0;
 
   return new Fl_PNM_Image(preview);
 }
@@ -363,7 +365,7 @@ ps_check(const char *name,      // I - Name of file
           "-sstdout=\"%%stderr\" -sOUTPUTFILE=\'%s\' \'%s\' 2>/dev/null",
           preview, outname);
 
-  if (system(command)) return 0;
+  if (fl_system(command)) return 0;
 
   return new Fl_PNM_Image(preview);
 }
diff --git a/test/table.cxx b/test/table.cxx
index 2e5f0f639..1a540ea4f 100644
--- a/test/table.cxx
+++ b/test/table.cxx
@@ -2,12 +2,6 @@
 // exercisetablerow -- Exercise all aspects of the Fl_Table_Row widget
 //
 
-#include <stdio.h>
-#include <string.h>
-#ifdef _WIN32
-#include <stdlib.h>     // atoi
-#endif /* _WIN32 */
-
 #include <FL/Fl.H>
 #include <FL/Fl_Window.H>
 #include <FL/Fl_Input.H>
@@ -18,6 +12,10 @@
 #include <FL/Fl_Table_Row.H>
 #include <FL/Fl_Simple_Terminal.H>
 
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>     // atoi
+
 #define TERMINAL_HEIGHT 120
 
 // Globals
diff --git a/test/unittests.cxx b/test/unittests.cxx
index ca04aac62..22e6220a2 100644
--- a/test/unittests.cxx
+++ b/test/unittests.cxx
@@ -1,7 +1,7 @@
 //
 // Unit tests for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2017 by Bill Spitzak and others.
+// Copyright 1998-2021 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -27,8 +27,9 @@
 #include <FL/Fl_Help_View.H>
 #include <FL/Fl_Group.H>
 #include <FL/Fl_Box.H>
-#include <FL/fl_draw.H>         // fl_text_extents()
-#include <FL/fl_string.h>       // fl_strdup()
+#include <FL/fl_draw.H>     // fl_text_extents()
+#include <FL/fl_string.h>   // fl_strdup()
+#include <stdlib.h>         // malloc, free
 
 // WINDOW/WIDGET SIZES
 #define MAINWIN_W       700                             // main window w()