From: Paul Eggert <eggert@cs.ucla.edu>
Date: Tue, 30 Aug 2011 16:27:26 +0000 (-0700)
Subject: * dbusbind.c (signature_cat): New function.
X-Git-Tag: emacs-pretest-24.0.90~104^2~153^2~1^2~10
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=2be7d7020619ebbdfb3df2bc2c3fcc3123bcedc0;p=emacs.git

* dbusbind.c (signature_cat): New function.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index 1de15f4796e..e6c58903f03 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,4 +1,4 @@
-2011-08-29  Paul Eggert  <eggert@cs.ucla.edu>
+2011-08-30  Paul Eggert  <eggert@cs.ucla.edu>
 
 	sprintf-related integer and memory overflow issues.
 
@@ -20,7 +20,8 @@
 	(esprintf, esnprintf, exprintf, evxprintf): New decls.
 	* window.h (command_loop_level, minibuf_level): Reflect API changes.
 
-	* dbusbind.c (xd_signature, Fdbus_register_signal):
+	* dbusbind.c (signature_cat): New function.
+	(xd_signature, Fdbus_register_signal):
 	Do not overrun buffer; instead, report string overflow.
 
 	* dispnew.c (add_window_display_history): Don't overrun buffer.
diff --git a/src/dbusbind.c b/src/dbusbind.c
index 005d521c1db..f7422ca2ddc 100644
--- a/src/dbusbind.c
+++ b/src/dbusbind.c
@@ -259,6 +259,18 @@ xd_symbol_to_dbus_type (Lisp_Object object)
     }									\
   while (0)
 
+/* Append to SIGNATURE the a copy of X, making sure SIGNATURE does
+   not become too long.  */
+static void
+signature_cat (char *signature, char const *x)
+{
+  ptrdiff_t siglen = strlen (signature);
+  ptrdiff_t xlen = strlen (x);
+  if (DBUS_MAXIMUM_SIGNATURE_LENGTH - xlen <= siglen)
+    string_overflow ();
+  strcat (signature, x);
+}
+
 /* Compute SIGNATURE of OBJECT.  It must have a form that it can be
    used in dbus_message_iter_open_container.  DTYPE is the DBusType
    the object is related to.  It is passed as argument, because it
@@ -388,10 +400,10 @@ xd_signature (char *signature, unsigned int dtype, unsigned int parent_type, Lis
 	{
 	  subtype = XD_OBJECT_TO_DBUS_TYPE (CAR_SAFE (elt));
 	  xd_signature (x, subtype, dtype, CAR_SAFE (XD_NEXT_VALUE (elt)));
-	  strcat (signature, x);
+	  signature_cat (signature, x);
 	  elt = CDR_SAFE (XD_NEXT_VALUE (elt));
 	}
-      strcat (signature, DBUS_STRUCT_END_CHAR_AS_STRING);
+      signature_cat (signature, DBUS_STRUCT_END_CHAR_AS_STRING);
       break;
 
     case DBUS_TYPE_DICT_ENTRY:
@@ -412,7 +424,7 @@ xd_signature (char *signature, unsigned int dtype, unsigned int parent_type, Lis
       elt = XD_NEXT_VALUE (elt);
       subtype = XD_OBJECT_TO_DBUS_TYPE (CAR_SAFE (elt));
       xd_signature (x, subtype, dtype, CAR_SAFE (XD_NEXT_VALUE (elt)));
-      strcat (signature, x);
+      signature_cat (signature, x);
 
       if (!XD_BASIC_DBUS_TYPE (subtype))
 	wrong_type_argument (intern ("D-Bus"), CAR_SAFE (XD_NEXT_VALUE (elt)));
@@ -421,14 +433,14 @@ xd_signature (char *signature, unsigned int dtype, unsigned int parent_type, Lis
       elt = CDR_SAFE (XD_NEXT_VALUE (elt));
       subtype = XD_OBJECT_TO_DBUS_TYPE (CAR_SAFE (elt));
       xd_signature (x, subtype, dtype, CAR_SAFE (XD_NEXT_VALUE (elt)));
-      strcat (signature, x);
+      signature_cat (signature, x);
 
       if (!NILP (CDR_SAFE (XD_NEXT_VALUE (elt))))
 	wrong_type_argument (intern ("D-Bus"),
 			     CAR_SAFE (CDR_SAFE (XD_NEXT_VALUE (elt))));
 
       /* Closing signature.  */
-      strcat (signature, DBUS_DICT_ENTRY_END_CHAR_AS_STRING);
+      signature_cat (signature, DBUS_DICT_ENTRY_END_CHAR_AS_STRING);
       break;
 
     default: