Add test for jabber-disco hashing

Use example from XEP-0115.

tests/Makefile.am

@@ -2,4 +2,5 @@
 # check" or "make distcheck" to work with earlier versions.
 LOG_COMPILER = env top_builddir=$(top_builddir) $(EMACS) -batch -L $(top_builddir) -L $(top_srcdir) -L $(srcdir) -l
 TESTS = load-all.el skip-tag-forward.el history.el jabberd.el nick-change-fail.el
+TESTS += caps-hash.el
 dist_noinst_DATA = $(TESTS)

tests/caps-hash.el

@@ -0,0 +1,51 @@
+;; Test disco hash against examples in XEP-0115
+
+(message "Let's go")
+(condition-case e
+    (require 'jabber-disco)
+  (error
+   (message "disco bad! %S" e)))
+(message "more")
+(condition-case e
+    (require 'jabber-widget)
+  (error
+   (message "bad! %S" e)))
+(message "done!")
+
+(let ((query
+       (with-temp-buffer
+	 (insert "<query xmlns='http://jabber.org/protocol/disco#info'
+         node='http://psi-im.org#q07IKJEyjvHSyhy//CH0CxmKi8w='>
+    <identity xml:lang='en' category='client' name='Psi 0.11' type='pc'/>
+    <identity xml:lang='el' category='client' name='Ψ 0.11' type='pc'/>
+    <feature var='http://jabber.org/protocol/caps'/>
+    <feature var='http://jabber.org/protocol/disco#info'/>
+    <feature var='http://jabber.org/protocol/disco#items'/>
+    <feature var='http://jabber.org/protocol/muc'/>
+    <x xmlns='jabber:x:data' type='result'>
+      <field var='FORM_TYPE' type='hidden'>
+        <value>urn:xmpp:dataforms:softwareinfo</value>
+      </field>
+      <field var='ip_version'>
+        <value>ipv4</value>
+        <value>ipv6</value>
+      </field>
+      <field var='os'>
+        <value>Mac</value>
+      </field>
+      <field var='os_version'>
+        <value>10.5.1</value>
+      </field>
+      <field var='software'>
+        <value>Psi</value>
+      </field>
+      <field var='software_version'>
+        <value>0.11</value>
+      </field>
+    </x>
+  </query>")
+	 (car (xml-parse-region (point-min) (point-max))))))
+  (message "parsed xml")
+  (unless (equal "q07IKJEyjvHSyhy//CH0CxmKi8w="
+		 (jabber-caps-ver-string query "sha-1"))
+    (error "Incorrect caps hash")))