Use a stronger X font definition for X11_MessageBox on UTF-8 X11 seemed to be confused by the broad definition, so WEIGHT_NAME, SLANT and SETWIDTH_NAME were defined, thus fixing the font lookup on some systems (tested on Mageia 6 with X11 1.19.1). Fixes bug 3571.
diff --git a/src/video/x11/SDL_x11messagebox.c b/src/video/x11/SDL_x11messagebox.c
index 0877652..73df899 100644
--- a/src/video/x11/SDL_x11messagebox.c
+++ b/src/video/x11/SDL_x11messagebox.c
@@ -50,7 +50,7 @@
#define MIN_DIALOG_HEIGHT 100 /* Minimum dialog height */
static const char g_MessageBoxFontLatin1[] = "-*-*-medium-r-normal--0-120-*-*-p-0-iso8859-1";
-static const char g_MessageBoxFont[] = "-*-*-*-*-*-*-*-120-*-*-*-*-*-*";
+static const char g_MessageBoxFont[] = "-*-*-medium-r-normal--*-120-*-*-*-*-*-*";
static const SDL_MessageBoxColor g_default_colors[ SDL_MESSAGEBOX_COLOR_MAX ] = {
{ 56, 54, 53 }, /* SDL_MESSAGEBOX_COLOR_BACKGROUND, */