Add note about semicolon in command. Closes #857

Author: mnaberez

docs/configuration.rst

@@ -606,6 +606,14 @@ where specified.
   responsible for daemonizing its subprocesses (see
   :ref:`nondaemonizing_of_subprocesses`).
 
+  .. note::
+
+    The command will be truncated if it looks like a config file comment,
+    e.g. ``command=bash -c 'foo ; bar'`` will be truncated to
+    ``command=bash -c 'foo ``.  Quoting will not prevent this behavior,
+    since the configuration file reader does not parse the command like
+    a shell would.
+
   *Default*: No default.
 
   *Required*:  Yes.

supervisor/skel/sample.conf

@@ -6,9 +6,11 @@
 ; Notes:
 ;  - Shell expansion ("~" or "$HOME") is not supported.  Environment
 ;    variables can be expanded using this syntax: "%(ENV_HOME)s".
-;  - Comments must have a leading space: "a=b ;comment" not "a=b;comment".
 ;  - Quotes around values are not supported, except in the case of
 ;    the environment= options as shown below.
+;  - Comments must have a leading space: "a=b ;comment" not "a=b;comment".
+;  - Command will be truncated if it looks like a config file comment, e.g.
+;    "command=bash -c 'foo ; bar'" will truncate to "command=bash -c 'foo ".
 
 [unix_http_server]
 file=/tmp/supervisor.sock   ; the path to the socket file