Open Radar

 
Summary:
Trying to edit the name of a custom header used in the “One and Only Junk Rule” (i.e. the rule set as a custom action in the Junk preference pane of Mail) will fail: Mail.app always resets it to the form previously used in the O&OJR.

Steps to Reproduce:
1. start Mail.app
3. open its preferences (Cmd-,) and select the Junk pane
4. set Junk handling to use a custom Action
5. edit the O&OJR to use a custom header named “X-Purgate-Type” with a value of “Foo”
6. quit Mail
7. start Mail.app in it
8. open its preferences (Cmd-,) and select the Junk pane
9. edit the header list in the rule; change the custom header name to “X-foo-bar”
10. quit Mail and restart it
11. open its preferences (Cmd-,) and select the Junk pane

Expected Results:
The O&OJR uses a header named “X-foo-bar”; that header is to be found in the custom header list.

Actual Results:
The O&OJR uses a header named ”X-Purgate-Type”; no “X-foo-bar” header is found in the custom header list.

If the actual results are not reproducible, repeat the Steps to Reproduce, inserting “get a 10.9.5 VM” before step 1. and “upgrade the VM to 10.10 DP 8 with Mail 8 (1985.4)” between steps 6. and 7.)

Notes:
* Observing ~/Library/Mail/V2/MailData/UnsyncedRules.plist during the above operations shows the header edit from step 9. is never actually written back to the prefs file. 
* Manually editing the plist to change the header name yields the expected result (i.e. the custom header dialog shows the edited form).