add support for valueless searches..

ui/fixtures/cmd.search.json

@@ -10,7 +10,7 @@
 },
 {
 	"title": "add tag b",
-	"cmd": [ "modify", "+tag=bar", "+dc:creator=John-Mark Gurney", "test.txt" ]
+	"cmd": [ "modify", "+tag=bar", "+dc:creator=John-Mark Gurney", "+other=baz", "test.txt" ]
 },
 {
 	"special": "verify store object cnt",
@@ -31,5 +31,15 @@
 	"title": "search no tag bar",
 	"cmd": [ "search", "file", "-tag=bar" ],
 	"stdout_re": "/newfile.txt\n$"
+},
+{
+	"title": "search no other",
+	"cmd": [ "search", "file", "-other" ],
+	"stdout_re": "/newfile.txt\n$"
+},
+{
+	"title": "search other",
+	"cmd": [ "search", "file", "+other" ],
+	"stdout_re": "/test.txt\n$"
 }
 ]

ui/medashare/cli.py

@@ -1426,12 +1426,23 @@ def cmd_search(options, persona, objstr, cache):
 	def testfun(x, s=searches):
 		try:
 			for i in s:
-				op, key, value = i
+				try:
+					op, key, value = i
+				except ValueError:
+					op, key = i
+					value = None
+
 				if op == '+':
-					if value not in x[key]:
+					if value is None:
+						if key not in x:
+							return False
+					elif value not in x[key]:
 						return False
 				elif op == '-':
-					if value in x[key]:
+					if value is None:
+						if key in x:
+							return False
+					elif value in x[key]:
 						return False
 				else:
 					raise ValueError('unhandled op: %s' % repr(op))