RFE: add --field-json JSONSTRING for complex custom fields #163

Hello!

The RHBZ utilizes a custom field Verififed (cf_verified) which accepts multiple values. However, with the current python-bugzilla it doesn't seem to be possible to edit this field:

$ bugzilla modify --private --field cf_verified="Tested" 1858220

Server error: <Fault -32000: 'Can\'t use string ("Tested") as an ARRAY ref while "strict refs" in use at /var/www/html/bugzilla/Bugzilla/Util.pm line 496.\n'>

Going through the documentation and source code, there's already support for such fields, but the support is limited to predefined set:

Fields that take multiple values have a special input format.
Append: --cc=foo@example.com
Overwrite: --cc==foo@example.com
Remove: --cc=-foo@example.com
Options that accept this format: --cc, --blocked, --dependson,
--groups, --tags, whiteboard fields.

After monkey-patching my python-bugzilla locally, I made it work with:

diff --git a/bugzilla/_cli.py b/bugzilla/_cli.py
index d5035cc..7058c47 100755
--- a/bugzilla/_cli.py
+++ b/bugzilla/_cli.py
@@ -441,7 +441,8 @@ def _merge_field_opts(query, fields, parser):
     for f in fields:
         try:
             f, v = f.split('=', 1)
-            query[f] = v
+            query[f] = _parse_triset(v, checkplus=False, checkminus=False,
+                                     checkequal=False, splitcomma=True)[0]
         except Exception:
             parser.error("Invalid field argument provided: %s" % (f))
 

but I have no idea if this solution is universal enough to not break other stuff. Would it be possible to make support for multi-value custom fields official somehow?

Thanks!