AttributeError: 'list' object has no attribute 'lower'

[Ryan J Ollos]

Found in the logs:

[pid 25608 140573411886848] 2016-02-04 18:19:12,083 Trac[main] ERROR: Internal Server Error: <RequestWithSession "GET '/browser/trunk/trac/ticket/model.py?rev=6512&rev=6512'">, referrer None
Traceback (most recent call last):
  File "/usr/local/virtualenv/1.1dev/lib/python2.7/site-packages/trac/web/main.py", line 607, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/local/virtualenv/1.1dev/lib/python2.7/site-packages/trac/web/main.py", line 256, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/local/virtualenv/1.1dev/lib/python2.7/site-packages/trac/versioncontrol/web_ui/browser.py", line 335, in process_request
    if rev.lower() in ('', 'head'):
AttributeError: 'list' object has no attribute 'lower'

I recall Jun reporting a similar issue with duplicated arguments. I'll need to search for that.

[Ryan J Ollos]

Replying to Ryan J Ollos:

I recall Jun reporting a similar issue with duplicated arguments. I'll need to search for that.

I was thinking of the issues discussed in comment:4:ticket:10907 and the comments that follow.

[Ryan J Ollos]

The traceback could be avoided with the following change:

trac/versioncontrol/web_ui/browser.py

@@ -332 +332 @@
             req.redirect(presel)
 
         path = req.args.get('path', '/')
-        rev = req.args.get('rev', '')
+        rev = req.args.getfirst('rev', '')
         if rev.lower() in ('', 'head'):
             rev = None
         format = req.args.get('format')

Another possibility would be to add an as_str method, following the pattern suggested in comment:5:ticket:12325.

However, it's worth considering to just close this as wontfix. I rarely see the issue in the logs, and my main goal is to fix issues that are frequent in the logs. I'd like to reduce the noisiness of the logs so I can review them faster each day for the dozen or so sites that I monitor, so that real issues can be spotted and fixed proactively. Even now there is so much noise in the logs that it takes 10-20 minutes to review them each day, despite pre-processing that aggregates the logs and filters out HTTPNotFound, HTTPBadRequest, etc …

[Ryan J Ollos]

Replying to Ryan J Ollos:

However, it's worth considering to just close this as wontfix. I rarely see the issue in the logs, and my main goal is to fix issues that are frequent in the logs. I'd like to reduce the noisiness of the logs so I can review them faster each day for the dozen or so sites that I monitor, so that real issues can be spotted and fixed proactively. Even now there is so much noise in the logs that it takes 10-20 minutes to review them each day, despite pre-processing that aggregates the logs and filters out HTTPNotFound, HTTPBadRequest, etc …

The noise in the logs in significantly reduced now that all monitored sites are running Trac 1.0.10 or very recent Trac 1.2dev.

[Ryan J Ollos]

Another similar case:

[pid 28869 139845353346816] 2016-04-03 20:02:58,023 Trac[main] ERROR: Internal Server Error: <RequestWithSession "GET '/timeline?from=2016-02-19T11%3A12%3A59%2B01%3A00&precision=second&from=Feb+19%2C+2016&daysback=7&authors=&changeset=on&repo-=on&repo-cboos.git=on&repo-cboos.hg=on&repo-jomae.git=on&repo-jomae.hg=on&repo-mercurial-plugin=on&repo-mirror=on&repo-psuter.git=on&repo-psuter.hg=on&repo-rblank=on&repo-rjollos.git=on&repo-ticket-links=on&milestone=on&ticket=on&wiki=on&sfp_email=&sfph_mail=&update=Update'">, referrer None
Traceback (most recent call last):
  File "/usr/local/virtualenv/1.1dev/lib/python2.7/site-packages/trac/web/main.py", line 607, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/local/virtualenv/1.1dev/lib/python2.7/site-packages/trac/web/main.py", line 256, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/local/virtualenv/1.1dev/lib/python2.7/site-packages/trac/timeline/web_ui.py", line 114, in process_request
    reqfromdate = req.args['from'].strip()
AttributeError: 'list' object has no attribute 'strip'

[Ryan J Ollos]

I'm going to fix a few instances, such as comment:5.

trac/timeline/web_ui.py

@@ -90 +90 @@
     def process_request(self, req):
         req.perm.assert_permission('TIMELINE_VIEW')
 
-        format = req.args.get('format')
-        maxrows = as_int(req.args.get('max'), 50 if format == 'rss' else 0)
+        format = req.args.getfirst('format')
+        default_maxrows = 50 if format == 'rss' else 0
+        maxrows = as_int(req.args.getfirst('max'), default_maxrows)
         lastvisit = int(req.session.get('timeline.lastvisit', '0'))
 
         # indication of new events is unchanged when form is updated by user
@@ -109 +110 @@
         precisedate = precision = None
         if 'from' in req.args:
             # Acquire from date only from non-blank input
-            reqfromdate = req.args['from'].strip()
+            reqfromdate = req.args.getfirst('from').strip()
             if reqfromdate:
                 try:
                     precisedate = user_time(req, parse_date, reqfromdate)
@@ -117 +118 @@
                     add_warning(req, e)
                 else:
                     fromdate = precisedate.astimezone(req.tz)
-            precision = req.args.get('precision', '')
+            precision = req.args.getfirst('precision', '')
             if precision.startswith('second'):
                 precision = timedelta(seconds=1)
             elif precision.startswith('minute'):
@@ -130 +131 @@
                                         fromdate.day, 23, 59, 59, 999999),
                                req.tz)
 
-        daysback = as_int(req.args.get('daysback'),
+        daysback = as_int(req.args.getfirst('daysback'),
                           90 if format == 'rss' else None)
         if daysback is None:
             daysback = as_int(req.session.get('timeline.daysback'), None)
@@ -140 +141 @@
         if self.max_daysback >= 0:
             daysback = min(self.max_daysback, daysback)
 
-        authors = req.args.get('authors')
+        authors = req.args.getfirst('authors')
         if authors is None and format != 'rss':
             authors = req.session.get('timeline.authors')
         authors = (authors or '').strip()

[Ryan J Ollos]

Fixed on 1.0-stable in [14700], merged to trunk in [14701].