STR#2086 related Fixes :

This one was really tough to track, understand:
In fact, 
the problem was comming from the misplacement of the menu window,
which itself came from invalid measurement,
which itself came from invalid fl_witdh() measurement,
but only when fl_gc is not valid because fl_width() relies on Win32 on the call
of GetTextExtentPoint32W which can't succeed if the HDC(here fl_gc) is not valid !

Now the fix:
A best-effort algorithm has been furthered to supply a valid fltk hdc if we can have one or a screen hdc if no fltk window is found by fl::first_window().

Note that when fl_gc is NULL inside fl_width() call, it can happen that Fl_Window::current() is not null but invalid (already deleted).
Finally, in the case of the buggy menu window observed here, this  fl_gc was set to NULL just after an Fl_Menu_Window deletion and re-creation in Fl_Menu_Item::pulldown().

Also added a comment to describe the new fl_width() behavior.



git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6540 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

src/Fl_Menu.cxx

@@ -80,7 +80,7 @@ const Fl_Menu_Item* Fl_Menu_Item::next(int n) const {
 }
 
 // appearance of current menus are pulled from this parent widget:
-static const Fl_Menu_* button;
+static const Fl_Menu_* button=0;
 
 ////////////////////////////////////////////////////////////////
 
@@ -320,7 +320,8 @@ menuwindow::menuwindow(const Fl_Menu_Item* m, int X, int Y, int Wp, int Hp,
   if (t) Wtitle = t->measure(&Htitle, button) + 12;
   int W = 0;
   if (m) for (; m->text; m = m->next()) {
-    int hh; int w1 = m->measure(&hh, button);
+    int hh; 
+    int w1 = m->measure(&hh, button);
     if (hh+LEADING>itemheight) itemheight = hh+LEADING;
     if (m->flags&(FL_SUBMENU|FL_SUBMENU_POINTER)) w1 += 14;
     if (w1 > W) W = w1;
@@ -541,7 +542,7 @@ struct menustate {
   menuwindow* fakemenu; // kludge for buttons in menubar
   int is_inside(int mx, int my);
 };
-static menustate* p;
+static menustate* p=0;
 
 // return 1 if the coordinates are inside any of the menuwindows
 int menustate::is_inside(int mx, int my) {
@@ -826,7 +827,7 @@ const Fl_Menu_Item* Fl_Menu_Item::pulldown(
     if (pp.current_item == oldi) continue;}
     // only do rest if item changes:
 
-    delete pp.fakemenu; pp.fakemenu = 0; // turn off "menubar button"
+    if(pp.fakemenu) {delete pp.fakemenu; pp.fakemenu = 0;} // turn off "menubar button"
 
     if (!pp.current_item) { // pointing at nothing
       // turn off selection in deepest menu, but don't erase other menus:
@@ -834,7 +835,7 @@ const Fl_Menu_Item* Fl_Menu_Item::pulldown(
       continue;
     }
 
-    delete pp.fakemenu; pp.fakemenu = 0;
+    if(pp.fakemenu) {delete pp.fakemenu; pp.fakemenu = 0;}
     initial_item = 0; // stop the startup code
     pp.p[pp.menu_number]->autoscroll(pp.item_number);
 

src/fl_draw.cxx

@@ -368,7 +368,7 @@ void fl_measure(const char* str, int& w, int& h, int draw_symbols) {
   char buf[MAXBUF];
   int buflen;
   int lines;
-  double width;
+  double width=0;
   int W = 0;
   char symbol[2][255], *symptr;
   int symwidth[2], symtotal;

src/fl_font.cxx

@@ -26,7 +26,9 @@
 //
 
 #ifdef WIN32
+#ifndef WIN32_LEAN_AND_MEAN
 # define WIN32_LEAN_AND_MEAN
+#endif
 /* We require Windows 2000 features such as GetGlyphIndices */
 # if !defined(WINVER) || (WINVER < 0x0500)
 #  define WINVER 0x0500

src/fl_font_win32.cxx

@@ -182,11 +182,24 @@ double fl_width(unsigned int c) {
     fl_fontsize->width[r] = (int*) malloc(sizeof(int) * 0x0400);
     SIZE s;
     unsigned short i = 0, ii = r * 0x400;
+    // The following code is a best effort algorithm to further	a valid fl_gc
+    // if no fl_gc is available at the time we call fl_width()
+    // We first choose a gc from the first fltk window, 
+    // if it is null then the gc from the current screen (GetDC(NULL)).
+    // This should solve STR #2086
+    HDC gc = fl_gc;
+    HWND hWnd = 0;
+    if (!gc) {
+	gc = GetDC(hWnd);
+    }
+    if (!gc)
+	Fl::fatal("Invalid graphic context: fl_width() failed because no valid HDC was found!");
     for (; i < 0x400; i++) {
-      GetTextExtentPoint32W(fl_gc, (WCHAR*)&ii, 1, &s);
+      GetTextExtentPoint32W(gc, (WCHAR*)&ii, 1, &s);
       fl_fontsize->width[r][i] = s.cx;
       ii++;
     }
+    if (gc && gc!=fl_gc) ReleaseDC(hWnd, gc);
   }
   return (double) fl_fontsize->width[r][c & 0x03FF];
 }