Fix uninitialized vars in calls to fl_clip_box() (issue #6)

The main fixes are only to avoid static code analyzer warnings reported
in issue #5, but there are also minor bug fixes included. These bug
fixes are more of theoretical concerns though.

Close #6.

8 files changed, 33 insertions, 28 deletions

diff --git a/src/drivers/Android/Fl_Android_Window_Driver.cxx b/src/drivers/Android/Fl_Android_Window_Driver.cxx
index 5781c0361..7a3e276fd 100644
--- a/src/drivers/Android/Fl_Android_Window_Driver.cxx
+++ b/src/drivers/Android/Fl_Android_Window_Driver.cxx
@@ -3,7 +3,7 @@
 //
 // Definition of Android window driver.
 //
-// Copyright 2018 by Bill Spitzak and others.
+// Copyright 2018-2020 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
@@ -510,7 +510,8 @@ void Fl_WinAPI_Window_Driver::flush_double()
     fl_end_offscreen();
   }
 
-  int X,Y,W,H; fl_clip_box(0,0,w(),h(),X,Y,W,H);
+  int X = 0, Y = 0, W = 0, H = 0;
+  fl_clip_box(0, 0, w(), h(), X, Y, W, H);
   if (other_xid) fl_copy_offscreen(X, Y, W, H, other_xid, X, Y);
 }
 
@@ -540,7 +541,8 @@ void Fl_WinAPI_Window_Driver::flush_overlay()
   }
 
   if (eraseoverlay) fl_clip_region(0);
-  int X, Y, W, H; fl_clip_box(0, 0, w(), h(), X, Y, W, H);
+  int X = 0, Y = 0, W = 0, H = 0;
+  fl_clip_box(0, 0, w(), h(), X, Y, W, H);
   if (other_xid) fl_copy_offscreen(X, Y, W, H, other_xid, X, Y);
 
   if (overlay() == oWindow) oWindow->draw_overlay();
diff --git a/src/drivers/GDI/Fl_GDI_Graphics_Driver_image.cxx b/src/drivers/GDI/Fl_GDI_Graphics_Driver_image.cxx
index a4f4a472c..0533b3b5f 100644
--- a/src/drivers/GDI/Fl_GDI_Graphics_Driver_image.cxx
+++ b/src/drivers/GDI/Fl_GDI_Graphics_Driver_image.cxx
@@ -3,7 +3,7 @@
 //
 // Windows image drawing code for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2020 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
@@ -125,8 +125,8 @@ static void innards(const uchar *buf, int X, int Y, int W, int H,
 
   if (!linedelta) linedelta = W*fl_abs(delta);
 
-  int x, y, w, h;
-  fl_clip_box(X,Y,W,H,x,y,w,h);
+  int x = 0, y = 0, w = 0, h = 0;
+  fl_clip_box(X, Y, W, H, x, y, w, h);
   if (w<=0 || h<=0) return;
   if (buf) buf += (x-X)*delta + (y-Y)*linedelta;
 
diff --git a/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_rect.cxx b/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_rect.cxx
index 2af56c55c..a0ce203ea 100644
--- a/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_rect.cxx
+++ b/src/drivers/OpenGL/Fl_OpenGL_Graphics_Driver_rect.cxx
@@ -3,7 +3,7 @@
 //
 // Rectangle drawing routines for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2017 by Bill Spitzak and others.
+// Copyright 1998-2020 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
@@ -172,7 +172,7 @@ void Fl_OpenGL_Graphics_Driver::push_clip(int x, int y, int w, int h) {
 
 int Fl_OpenGL_Graphics_Driver::clip_box(int x, int y, int w, int h, int &X, int &Y, int &W, int &H) {
   // TODO: implement OpenGL clipping
-  X = x; Y = y; W = w, H = h;
+  X = x; Y = y; W = w; H = h;
   return 0;
 }
 
diff --git a/src/drivers/Pico/Fl_Pico_Graphics_Driver.cxx b/src/drivers/Pico/Fl_Pico_Graphics_Driver.cxx
index e11c13437..ace311323 100644
--- a/src/drivers/Pico/Fl_Pico_Graphics_Driver.cxx
+++ b/src/drivers/Pico/Fl_Pico_Graphics_Driver.cxx
@@ -3,7 +3,7 @@
 //
 // Rectangle drawing routines for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2016 by Bill Spitzak and others.
+// Copyright 1998-2020 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
@@ -195,6 +195,7 @@ void Fl_Pico_Graphics_Driver::push_clip(int x, int y, int w, int h)
 
 int Fl_Pico_Graphics_Driver::clip_box(int x, int y, int w, int h, int &X, int &Y, int &W, int &H)
 {
+  X = x; Y = y; W = w; H = h;
   return 0;
 }
 
diff --git a/src/drivers/PostScript/Fl_PostScript.cxx b/src/drivers/PostScript/Fl_PostScript.cxx
index 1b6fed13e..5e7f6b4e0 100644
--- a/src/drivers/PostScript/Fl_PostScript.cxx
+++ b/src/drivers/PostScript/Fl_PostScript.cxx
@@ -3,7 +3,7 @@
 //
 // Classes Fl_PostScript_File_Device and Fl_PostScript_Graphics_Driver for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2016 by Bill Spitzak and others.
+// Copyright 2010-2020 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
@@ -1341,16 +1341,16 @@ void Fl_PostScript_Graphics_Driver::pop_clip() {
     recover();
 }
 
-int Fl_PostScript_Graphics_Driver::clip_box(int x, int y, int w, int h, int &X, int &Y, int &W, int &H){
-  if(!clip_){
-    X=x;Y=y;W=w;H=h;
+int Fl_PostScript_Graphics_Driver::clip_box(int x, int y, int w, int h, int &X, int &Y, int &W, int &H) {
+  if (!clip_) {
+    X = x; Y = y; W = w; H = h;
     return 1;
   }
-  if(clip_->w < 0){
-    X=x;Y=y;W=w;H=h;
+  if (clip_->w < 0) {
+    X = x; Y = y; W = w; H = h;
     return 1;
   }
-  int ret=0;
+  int ret = 0;
   if (x > (X=clip_->x)) {X=x; ret=1;}
   if (y > (Y=clip_->y)) {Y=y; ret=1;}
   if ((x+w) < (clip_->x+clip_->w)) {
@@ -1377,12 +1377,12 @@ int Fl_PostScript_Graphics_Driver::clip_box(int x, int y, int w, int h, int &X,
   return ret;
 }
 
-int Fl_PostScript_Graphics_Driver::not_clipped(int x, int y, int w, int h){
-  if(!clip_) return 1;
-  if(clip_->w < 0) return 1;
-  int X, Y, W, H;
+int Fl_PostScript_Graphics_Driver::not_clipped(int x, int y, int w, int h) {
+  if (!clip_) return 1;
+  if (clip_->w < 0) return 1;
+  int X = 0, Y = 0, W = 0, H = 0;
   clip_box(x, y, w, h, X, Y, W, H);
-  if(W) return 1;
+  if (W) return 1;
   return 0;
 }
 
diff --git a/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx b/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
index 78379712f..fb449754e 100644
--- a/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
+++ b/src/drivers/WinAPI/Fl_WinAPI_Window_Driver.cxx
@@ -3,7 +3,7 @@
 //
 // Definition of Apple Cocoa window driver.
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2020 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
@@ -334,7 +334,8 @@ void Fl_WinAPI_Window_Driver::flush_double()
     fl_graphics_driver->gc(sgc);
 #endif
   }
-  int X,Y,W,H; fl_clip_box(0,0,w(),h(),X,Y,W,H);
+  int X = 0, Y = 0, W = 0, H = 0;
+  fl_clip_box(0, 0, w(), h(), X, Y, W, H);
   if (other_xid) fl_copy_offscreen(X, Y, W, H, other_xid, X, Y);
 }
 
diff --git a/src/drivers/X11/Fl_X11_Window_Driver.cxx b/src/drivers/X11/Fl_X11_Window_Driver.cxx
index 1de2e5297..2ea16bf70 100644
--- a/src/drivers/X11/Fl_X11_Window_Driver.cxx
+++ b/src/drivers/X11/Fl_X11_Window_Driver.cxx
@@ -3,7 +3,7 @@
 //
 // Definition of X11 window driver.
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2020 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
@@ -234,7 +234,8 @@ void Fl_X11_Window_Driver::flush_double(int erase_overlay)
       fl_window = i->xid;
     }
   if (erase_overlay) fl_clip_region(0);
-  int X,Y,W,H; fl_clip_box(0,0,w(),h(),X,Y,W,H);
+  int X = 0, Y = 0, W = 0, H = 0;
+  fl_clip_box(0, 0, w(), h(), X, Y, W, H);
   if (other_xid) fl_copy_offscreen(X, Y, W, H, other_xid, X, Y);
 }
 
diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
index 688457a24..8fed7834b 100644
--- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
+++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_image.cxx
@@ -3,7 +3,7 @@
 //
 // Image drawing routines for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2018 by Bill Spitzak and others.
+// Copyright 1998-2020 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
@@ -474,8 +474,8 @@ static void innards(const uchar *buf, int X, int Y, int W, int H,
 {
   if (!linedelta) linedelta = W*abs(delta);
 
-  int dx, dy, w, h;
-  fl_clip_box(X,Y,W,H,dx,dy,w,h);
+  int dx = 0, dy = 0, w = 0, h = 0;
+  fl_clip_box(X, Y, W, H, dx, dy, w, h);
   if (w<=0 || h<=0) return;
   dx -= X;
   dy -= Y;