From 52d0c19fb779da1b0ba83fdbbebec7dd1ce0a59f Mon Sep 17 00:00:00 2001
From: Mook <mook.moz+com.github@gmail.com>
Date: Sun, 13 Apr 2014 19:41:22 -0700
Subject: [PATCH 1/2] `beet modify`: Treat arguments with : before = as
 queries, not modifications

This can be useful if the value being queried contains an equal sign.
---
 beets/ui/commands.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/beets/ui/commands.py b/beets/ui/commands.py
index cc5b14cfe..fd91c0dcd 100644
--- a/beets/ui/commands.py
+++ b/beets/ui/commands.py
@@ -1170,7 +1170,7 @@ def modify_func(lib, opts, args):
     for arg in args:
         if arg.endswith('!') and '=' not in arg and ':' not in arg:
             dels.append(arg[:-1])  # Strip trailing !.
-        elif '=' in arg:
+        elif '=' in arg and ':' not in arg.split('=', 1)[0]:
             mods.append(arg)
         else:
             query.append(arg)

From 12a5215afa0a0fe3d0aeb38d00a5547366258eae Mon Sep 17 00:00:00 2001
From: Mook <mook.moz+com.github@gmail.com>
Date: Sun, 13 Apr 2014 21:24:45 -0700
Subject: [PATCH 2/2] `beet modify`: Add simple argument parsing tests.

---
 beets/ui/commands.py | 31 +++++++++++++++++++------------
 test/test_ui.py      | 24 ++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/beets/ui/commands.py b/beets/ui/commands.py
index fd91c0dcd..a4cd77763 100644
--- a/beets/ui/commands.py
+++ b/beets/ui/commands.py
@@ -1145,6 +1145,24 @@ def modify_items(lib, mods, dels, query, write, move, album, confirm):
         for item in changed_items:
             item.try_write()
 
+
+def modify_parse_args(args):
+    """Split the arguments for the modify subcommand into query parts,
+    assignments (field=value), and deletions (field!).  Returns the result as
+    a three-tuple in that order.
+    """
+    mods = []
+    dels = []
+    query = []
+    for arg in args:
+        if arg.endswith('!') and '=' not in arg and ':' not in arg:
+            dels.append(arg[:-1])  # Strip trailing !.
+        elif '=' in arg and ':' not in arg.split('=', 1)[0]:
+            mods.append(arg)
+        else:
+            query.append(arg)
+    return (query, mods, dels)
+
 modify_cmd = ui.Subcommand('modify',
     help='change metadata fields', aliases=('mod',))
 modify_cmd.parser.add_option('-M', '--nomove', action='store_false',
@@ -1162,18 +1180,7 @@ modify_cmd.parser.add_option('-f', '--format', action='store',
 def modify_func(lib, opts, args):
     args = decargs(args)
 
-    # Split the arguments into query parts, assignments (field=value),
-    # and deletions (field!).
-    mods = []
-    dels = []
-    query = []
-    for arg in args:
-        if arg.endswith('!') and '=' not in arg and ':' not in arg:
-            dels.append(arg[:-1])  # Strip trailing !.
-        elif '=' in arg and ':' not in arg.split('=', 1)[0]:
-            mods.append(arg)
-        else:
-            query.append(arg)
+    (query, mods, dels) = modify_parse_args(args)
 
     if not mods and not dels:
         raise ui.UserError('no modifications specified')
diff --git a/test/test_ui.py b/test/test_ui.py
index 34d7104b4..d25c94e1f 100644
--- a/test/test_ui.py
+++ b/test/test_ui.py
@@ -238,6 +238,30 @@ class ModifyTest(_common.TestCase):
         mediafile = MediaFile(item.path)
         self.assertIsNone(mediafile.initial_key)
 
+    def test_arg_parsing_colon_query(self):
+        (query, mods, dels) = commands.modify_parse_args(["title:oldTitle",
+                                                          "title=newTitle"])
+        self.assertEqual(query, ["title:oldTitle"])
+        self.assertEqual(mods, ["title=newTitle"])
+
+    def test_arg_parsing_delete(self):
+        (query, mods, dels) = commands.modify_parse_args(["title:oldTitle",
+                                                          "title!"])
+        self.assertEqual(query, ["title:oldTitle"])
+        self.assertEqual(dels, ["title"])
+
+    def test_arg_parsing_query_with_exclaimation(self):
+        (query, mods, dels) = commands.modify_parse_args(["title:oldTitle!",
+                                                          "title=newTitle!"])
+        self.assertEqual(query, ["title:oldTitle!"])
+        self.assertEqual(mods, ["title=newTitle!"])
+
+    def test_arg_parsing_equals_in_value(self):
+        (query, mods, dels) = commands.modify_parse_args(["title:foo=bar",
+                                                          "title=newTitle"])
+        self.assertEqual(query, ["title:foo=bar"])
+        self.assertEqual(mods, ["title=newTitle"])
+
 
 class MoveTest(_common.TestCase):
     def setUp(self):