Merge branch 'release-4.16.1'

[i3/i3] / libi3 / root_atom_contents.c

diff --git a/libi3/root_atom_contents.c b/libi3/root_atom_contents.c
index cabaaf2c3965f70c27be20937dbee3c377cc8ccf..d6394d4bf2f7631fef52cb89454f32ca3a705664 100644 (file)
--- a/libi3/root_atom_contents.c
+++ b/libi3/root_atom_contents.c
@@ -2,37 +2,44 @@
  * vim:ts=4:sw=4:expandtab
  *
  * i3 - an improved dynamic tiling window manager
- * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
+ * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
  *
  */
+#include "libi3.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <stdbool.h>
 #include <limits.h>
+#include <stdlib.h>
+#include <math.h>
 
 #include <xcb/xcb.h>
 #include <xcb/xcb_aux.h>
 
-#include "libi3.h"
-
 /*
  * Try to get the contents of the given atom (for example I3_SOCKET_PATH) from
  * the X11 root window and return NULL if it doesn’t work.
  *
+ * If the provided XCB connection is NULL, a new connection will be
+ * established.
+ *
  * The memory for the contents is dynamically allocated and has to be
  * free()d by the caller.
  *
  */
-char *root_atom_contents(const char *atomname) {
-    xcb_connection_t *conn;
+char *root_atom_contents(const char *atomname, xcb_connection_t *provided_conn, int screen) {
     xcb_intern_atom_cookie_t atom_cookie;
     xcb_intern_atom_reply_t *atom_reply;
-    int screen;
-    char *content;
+    char *content = NULL;
+    size_t content_max_words = 256;
+    xcb_connection_t *conn = provided_conn;
 
-    if ((conn = xcb_connect(NULL, &screen)) == NULL ||
-        xcb_connection_has_error(conn))
+    if (provided_conn == NULL &&
+        ((conn = xcb_connect(NULL, &screen)) == NULL ||
+         xcb_connection_has_error(conn))) {
         return NULL;
+    }
 
     atom_cookie = xcb_intern_atom(conn, 0, strlen(atomname), atomname);
 
@@ -40,27 +47,49 @@ char *root_atom_contents(const char *atomname) {
     xcb_window_t root = root_screen->root;
 
     atom_reply = xcb_intern_atom_reply(conn, atom_cookie, NULL);
-    if (atom_reply == NULL)
-        return NULL;
+    if (atom_reply == NULL) {
+        goto out_conn;
+    }
 
     xcb_get_property_cookie_t prop_cookie;
     xcb_get_property_reply_t *prop_reply;
     prop_cookie = xcb_get_property_unchecked(conn, false, root, atom_reply->atom,
-                                             XCB_GET_PROPERTY_TYPE_ANY, 0, PATH_MAX);
+                                             XCB_GET_PROPERTY_TYPE_ANY, 0, content_max_words);
     prop_reply = xcb_get_property_reply(conn, prop_cookie, NULL);
-    if (prop_reply == NULL || xcb_get_property_value_length(prop_reply) == 0)
-        return NULL;
+    if (prop_reply == NULL) {
+        goto out_atom;
+    }
+    if (xcb_get_property_value_length(prop_reply) > 0 && prop_reply->bytes_after > 0) {
+        /* We received an incomplete value. Ask again but with a properly
+         * adjusted size. */
+        content_max_words += ceil(prop_reply->bytes_after / 4.0);
+        /* Repeat the request, with adjusted size */
+        free(prop_reply);
+        prop_cookie = xcb_get_property_unchecked(conn, false, root, atom_reply->atom,
+                                                 XCB_GET_PROPERTY_TYPE_ANY, 0, content_max_words);
+        prop_reply = xcb_get_property_reply(conn, prop_cookie, NULL);
+        if (prop_reply == NULL) {
+            goto out_atom;
+        }
+    }
+    if (xcb_get_property_value_length(prop_reply) == 0) {
+        goto out;
+    }
     if (prop_reply->type == XCB_ATOM_CARDINAL) {
         /* We treat a CARDINAL as a >= 32-bit unsigned int. The only CARDINAL
          * we query is I3_PID, which is 32-bit. */
-        if (asprintf(&content, "%u", *((unsigned int*)xcb_get_property_value(prop_reply))) == -1)
-            return NULL;
+        sasprintf(&content, "%u", *((unsigned int *)xcb_get_property_value(prop_reply)));
     } else {
-        if (asprintf(&content, "%.*s", xcb_get_property_value_length(prop_reply),
-                     (char*)xcb_get_property_value(prop_reply)) == -1)
-            return NULL;
+        sasprintf(&content, "%.*s", xcb_get_property_value_length(prop_reply),
+                  (char *)xcb_get_property_value(prop_reply));
     }
-    xcb_disconnect(conn);
+
+out:
+    free(prop_reply);
+out_atom:
+    free(atom_reply);
+out_conn:
+    if (provided_conn == NULL)
+        xcb_disconnect(conn);
     return content;
 }
-