[fix, AppImage] Add libXss.so.1 dummy (#826)

References <koreader/koreader#4627>.

Makefile

@@ -84,6 +84,7 @@ $(OUTPUT_DIR)/data:
 libs: \
 	$(if $(or $(SDL),$(ANDROID)),,$(OUTPUT_DIR)/libs/libkoreader-input.so) \
 	$(if $(or $(SDL),$(ANDROID)),$(OUTPUT_DIR)/libs/libblitbuffer.so,) \
+	$(if $(APPIMAGE),$(OUTPUT_DIR)/libs/libXss.so.1,) \
 	$(OUTPUT_DIR)/libs/libkoreader-lfs.so \
 	$(OUTPUT_DIR)/libs/libkoreader-djvu.so \
 	$(OUTPUT_DIR)/libs/libkoreader-cre.so \
@@ -135,6 +136,9 @@ $(OUTPUT_DIR)/libs/libwrap-mupdf.so: wrap-mupdf.c \
 			$(MUPDF_LIB)
 	$(CC) -I$(MUPDF_DIR)/include $(DYNLIB_CFLAGS) -o $@ $^
 
+$(OUTPUT_DIR)/libs/libXss.so.1: libxss-dummy.c
+	$(CC) $(DYNLIB_CFLAGS) -o $@ $^
+
 ffi/mupdf_h.lua: ffi-cdecl/mupdf_decl.c $(MUPDF_DIR)/include
 	CPPFLAGS="$(CFLAGS) -I. -I$(MUPDF_DIR)/include" $(FFI_CDECL) gcc ffi-cdecl/mupdf_decl.c $@
 

libxss-dummy.c

@@ -0,0 +1,19 @@
+// Dummy symbol resolver for AppImage
+// See https://github.com/koreader/koreader/issues/4627
+// Thanks to https://github.com/AppImage/pkg2appimage/issues/127#issuecomment-278397037
+#include <X11/Xlib.h>
+typedef unsigned long ulong;
+typedef unsigned int uint;
+typedef struct { Window window; int state; int kind; ulong til_or_since; ulong idle; ulong eventMask; } XScreenSaverInfo;
+Bool XScreenSaverQueryExtension(Display *dpy, int *event_base_return, int *error_base_return){}
+Status XScreenSaverQueryVersion(Display *dpy, int *major_version_return, int *minor_version_return){}
+XScreenSaverInfo *XScreenSaverAllocInfo(void){}
+Status XScreenSaverQueryInfo(Display *dpy, Drawable drawable, XScreenSaverInfo *saver_info){}
+void XScreenSaverSelectInput(register Display *dpy, Drawable drawable,  ulong mask){}
+void XScreenSaverSetAttributes(Display *dpy, Drawable drawable, int x, int y, uint width, uint height,
+  uint border_width, int depth, uint class, Visual *visual, ulong valuemask, XSetWindowAttributes *attributes){}
+void XScreenSaverUnsetAttributes(register Display *dpy, Drawable drawable){}
+Status XScreenSaverRegister(Display *dpy, int screen, XID xid, Atom type){}
+Status XScreenSaverUnregister(Display *dpy, int screen){}
+Status XScreenSaverGetRegistered(Display *dpy, int screen, XID *xid, Atom *type){}
+void XScreenSaverSuspend(Display *dpy, Bool suspend){}