Use xcb-util-xrm

Instead of using Xlib for parsing resource files, this now uses the
dedicated xcb-based library that is meant for exactly this task.

Fixes: https://github.com/awesomeWM/awesome/issues/1176
Signed-off-by: Uli Schlachter <psychon@znc.in>

.travis.yml

@@ -40,6 +40,10 @@ install:
   # Deps for functional tests.
   - sudo apt-get install -y dbus-x11 xterm xdotool xterm xvfb
 
+  # Need xorg-macros
+  - sudo apt-get install -y xutils-dev
+  - git clone --recursive https://github.com/Airblader/xcb-util-xrm.git && cd xcb-util-xrm && ./autogen.sh --prefix=/usr && make && sudo make install && cd -
+
   # Install Lua (per env).
   # Note that Lua 5.3 is installed manually, because it is not available in Ubuntu Trusty.
   - |

awesome.c

@@ -587,12 +587,7 @@ main(int argc, char **argv)
     XkbIgnoreExtension(True);
 
     /* X stuff */
-    globalconf.display = XOpenDisplay(NULL);
-    if (globalconf.display == NULL)
-        fatal("Cannot open display");
-    XSetEventQueueOwner(globalconf.display, XCBOwnsEventQueue);
-    globalconf.default_screen = XDefaultScreen(globalconf.display);
-    globalconf.connection = XGetXCBConnection(globalconf.display);;
+    globalconf.connection = xcb_connect(NULL, &globalconf.default_screen);
     if(xcb_connection_has_error(globalconf.connection))
         fatal("cannot open display (error %d)", xcb_connection_has_error(globalconf.connection));
 
@@ -622,6 +617,11 @@ main(int argc, char **argv)
 
     if (xcb_cursor_context_new(globalconf.connection, globalconf.screen, &globalconf.cursor_ctx) < 0)
         fatal("Failed to initialize xcb-cursor");
+    globalconf.xrmdb = xcb_xrm_database_from_default(globalconf.connection);
+    if (globalconf.xrmdb == NULL)
+        globalconf.xrmdb = xcb_xrm_database_from_string("");
+    if (globalconf.xrmdb == NULL)
+        fatal("Failed to initialize xcb-xrm");
 
     /* Did we get some usable data from the above X11 setup? */
     draw_test_cairo_xcb();

awesomeConfig.cmake

@@ -112,7 +112,6 @@ pkg_check_modules(AWESOME_REQUIRED REQUIRED
     gdk-pixbuf-2.0
     cairo
     x11
-    x11-xcb
     xcb-cursor
     xcb-randr
     xcb-xtest
@@ -129,7 +128,8 @@ pkg_check_modules(AWESOME_REQUIRED REQUIRED
     cairo-xcb
     libstartup-notification-1.0>=0.10
     xproto>=7.0.15
-    libxdg-basedir>=1.0.0)
+    libxdg-basedir>=1.0.0
+    xcb-xrm)
 
 if(NOT AWESOME_REQUIRED_FOUND OR NOT AWESOME_COMMON_REQUIRED_FOUND)
     message(FATAL_ERROR)

globalconf.h

@@ -30,6 +30,7 @@
 #include <xcb/xcb_icccm.h>
 #include <xcb/xcb_keysyms.h>
 #include <xcb/xcb_cursor.h>
+#include <xcb/xcb_xrm.h>
 #include <X11/Xresource.h>
 
 #include "objects/key.h"
@@ -73,12 +74,10 @@ DO_ARRAY(xcb_window_t, window, DO_NOTHING)
 /** Main configuration structure */
 typedef struct
 {
-    /** Xlib Display */
-    Display *display;
-    /** X Resources DB */
-    XrmDatabase xrmdb;
     /** Connection ref */
     xcb_connection_t *connection;
+    /** X Resources DB */
+    xcb_xrm_database_t *xrmdb;
     /** Default screen number */
     int default_screen;
     /** xcb-cursor context */

xrdb.c

@@ -26,23 +26,6 @@
 
 #include <string.h>
 
-/* \brief open X display and X Resources DB
- */
-static void xrdb_init(void) {
-  XrmInitialize(); // @TODO: it works without it but in docs it's said what it's
-                   // needed
-  if (!(globalconf.xrmdb = XrmGetDatabase(globalconf.display))) {
-
-    /* taken from xpbiff: */
-    /* >> what a hack; need to initialize dpy->db */
-    (void)XGetDefault(globalconf.display, "", "");
-    /**/
-
-    if (!(globalconf.xrmdb = XrmGetDatabase(globalconf.display)))
-      warn("Cannot open xrdb.");
-  }
-}
-
 /* \brief get value from X Resources DataBase
  * \param L The Lua VM state.
  * \return The number of elements pushed on stack.
@@ -52,26 +35,21 @@ static void xrdb_init(void) {
  * \lreturn string xrdb value or nil if not exists. \
  */
 int luaA_xrdb_get_value(lua_State *L) {
-  if (!globalconf.xrmdb)
-    xrdb_init();
-
-  char *resource_type;
-  int resource_code;
-  XrmValue resource_value;
     const char *resource_class = luaL_checkstring(L, 1);
     const char *resource_name = luaL_checkstring(L, 2);
+    char *result = NULL;
 
-  resource_code = XrmGetResource(globalconf.xrmdb, resource_name, resource_class,
-                                 &resource_type, &resource_value);
-  if (resource_code && (strcmp(resource_type, "String") == 0)) {
-    lua_pushstring(L, (char *)resource_value.addr);
-  } else {
+    if (xcb_xrm_resource_get_string(globalconf.xrmdb, resource_name, resource_class, &result) < 0 ) {
         if (strlen(resource_class))
             luaA_warn(L, "Failed to get xrdb value '%s' (class '%s').", resource_name, resource_class);
         else
             luaA_warn(L, "Failed to get xrdb value '%s'.", resource_name);
         lua_pushnil(L);
+    } else {
+        lua_pushstring(L, result);
+        p_delete(&result);
     }
+
     return 1;
 }