Added '--enable-opengl' flag to bypass the thread-safety check.

configure.in

@@ -18,6 +18,7 @@ LIBEXT=so       # library type .so or .a
 TRACE_MSGS=yes	# the TRACE() macro
 DEBUG_MSGS=yes	# the TRACE(), WARN(), and FIXME() macros.
 CURSES=yes
+OPENGL=normal
 
 AC_ARG_ENABLE(emulator,
 [  --disable-emulator      build only the Wine library, not the emulator],
@@ -31,6 +32,10 @@ AC_ARG_ENABLE(debug,
 [  --disable-debug         compile out all debugging messages],
 [if test "$enableval" = "no"; then DEBUG_MSGS="no"; fi])
 
+AC_ARG_ENABLE(opengl,
+[  --enable-opengl         force usage of OpenGL even if the latter is thread-safe],
+[if test "$enableval" = "no"; then OPENGL="no"; elif test "$enableval" = "yes"; then OPENGL="yes"; fi])
+
 AC_ARG_ENABLE(trace,
 [  --disable-trace         compile out TRACE messages],
 [if test "$enableval" = "no"; then TRACE_MSGS="no"; fi])
@@ -188,11 +193,13 @@ then
     fi
 
     dnl Check for the presence of Mesa
-    AC_CHECK_HEADERS(GL/gl.h GL/glx.h GL/osmesa.h)
+    if test $OPENGL = "yes" -o $OPENGL = "normal"
+    then
+	AC_CHECK_HEADERS(GL/gl.h GL/glx.h)
 	if test "$ac_cv_header_GL_gl_h" = "yes" -a "$ac_cv_header_GL_glx_h" = "yes"
 	then
 	    dnl Check for some problems due to old Mesa versions
-        AC_CACHE_CHECK("for up-to-date Mesa version", wine_cv_mesa_version_OK,
+	    AC_CACHE_CHECK("for up-to-date OpenGL version", wine_cv_mesa_version_OK,
 	      AC_TRY_COMPILE(
 		[#include <GL/gl.h>],
 		[GLenum test = GL_UNSIGNED_SHORT_5_6_5;],
@@ -202,7 +209,7 @@ then
             )
 
 	    dnl Check for the thread-safety of the OpenGL library
-        AC_CACHE_CHECK("for thread-safe Mesa version", 
+	    AC_CACHE_CHECK("for thread-safe OpenGL version", 
 			   wine_cv_mesa_version_threadsafe,
               [saved_libs=$LIBS
 	       LIBS="$X_LIBS -lGL"
@@ -212,7 +219,7 @@ then
 	       LIBS=$saved_libs]
 	    )
 
-        if test "$wine_cv_mesa_version_OK" = "yes" -a "$wine_cv_mesa_version_threadsafe" = "no"
+	    if test "$wine_cv_mesa_version_OK" = "yes" -a \( "$wine_cv_mesa_version_threadsafe" = "no" -o $OPENGL = "yes" \)
             then
 		dnl Check for the presense of the library
 		AC_CHECK_LIB(GL,glXCreateContext,
@@ -221,6 +228,7 @@ then
 			     MESA_SRCS='$(MESA_SRCS)'
 			     ,,
 			     $X_LIBS -lXext -lX11 -lm $X_EXTRA_LIBS)
+
 		if test "$ac_cv_lib_GL_glXCreateContext" = "no"
 		then
 			AC_CHECK_LIB(MesaGL,glXCreateContext,
@@ -233,12 +241,10 @@ then
 
 		dnl Check for the Color Table and Paletted Texture extensions
 		AC_CACHE_CHECK("for the OpenGL Color Index extension",dummy,
-              AC_TRY_COMPILE(
+			       AC_TRY_COMPILE([#include <GL/gl.h>],
-		[#include <GL/gl.h>],
 			                      [GLenum test = GL_COLOR_INDEX8_EXT;],
-		[AC_DEFINE(HAVE_GL_COLOR_TABLE)],
+					      [AC_DEFINE(HAVE_GL_COLOR_TABLE)],))
-	      )
+
-	    )
     	        if test "$ac_cv_lib_GL_glXCreateContext" = "no"
 		then
 			AC_CHECK_LIB(MesaGL,glColorTableEXT,AC_DEFINE(HAVE_GL_PALETTED_TEXTURE),,$X_LIBS -lXext -lX11 -lm $X_EXTRA_LIBS)
@@ -247,6 +253,7 @@ then
 		fi
 	     fi
 	 fi
+    fi
 
     CPPFLAGS="$ac_save_CPPFLAGS"
     X_DLLS='$(X_DLLS)'
@@ -1103,14 +1110,24 @@ then
   echo "*** support. Consider upgrading your Mesa libraries (http://www.mesa3d.org/)."
 fi
 
-if test "$wine_cv_mesa_version_threadsafe" = "yes"
+if test "$wine_cv_mesa_version_threadsafe" = "yes" -a $OPENGL = "normal"
 then
   echo
   echo "*** Warning: the OpenGL version you have installed relies on libpthread for"
-  echo "*** thread-safety. To prevent crashes, OpenGL support has been removed"
+  echo "*** thread-safety. To prevent crashes, OpenGL support has been removed."
-  echo "*** (while we work on a better fix)."
+  echo "*** A fix for glibc 2.1.3 that seem to work is included in this version of Wine,"
+  echo "*** start configure with '--enable-opengl' to force OpenGL support."
 fi
 
+if test "$wine_cv_mesa_version_threadsafe" = "yes" -a $OPENGL = "yes"
+then
+  echo
+  echo "*** Warning: you explicitely linked in a thread-safe OpenGL version. If you"
+  echo "*** experience unusual crashes on DirectDraw games, try first to disable OpenGL"
+  echo "*** support before reporting bugs."
+fi
+
+
 echo
 echo "Configure finished.  Do 'make depend && make' to compile Wine."
 echo

include/config.h.in

@@ -242,9 +242,6 @@
 /* Define if you have the <GL/glx.h> header file.  */
 #undef HAVE_GL_GLX_H
 
-/* Define if you have the <GL/osmesa.h> header file.  */
-#undef HAVE_GL_OSMESA_H
-
 /* Define if you have the <X11/Xlib.h> header file.  */
 #undef HAVE_X11_XLIB_H