System Information should be a unique list

[Ryan J Ollos]

While working on #12287 it occurred that two plugins might add the same package via System Information. The proposed change will make the System Information list unique.

trac/env.py

@@ -303 +303 @@
         info = self.systeminfo[:]
         for provider in self.system_info_providers:
             info.extend(provider.get_system_info() or [])
-        info.sort(key=lambda (name, version): (name != 'Trac', name.lower()))
-        return info
+        return sorted(set(info),
+                      key=lambda (name, ver): (name != 'Trac', name.lower()))
 
     # ISystemInfoProvider methods
 

[Ryan J Ollos]

Also, I think we should add name to the dictionary returned by trac.util.get_pkginfo, so that a plugin implementation of get_systeminfo can follow the pattern:

    def get_system_info(self):
        import dns
        pkginfo = get_pkginfo(dns)
        yield pkginfo['name'], pkginfo['version']

The change only needs to be made on 1.2dev though.

How about using get_pkginfo everywhere rather than relying on attributes that aren't consistent among packages and could be changed by the package author? For example, for Pillow I could only see to use:

>>> import PIL
>>> PIL.PILLOW_VERSION
'3.0.0'

However, get_pkginfo(PIL)['version'] seems much simpler. get_pkginfo(PIL).get('version', '') might be even safer.

Related: I'm still unsure of the complexity of the trac_version method that was created by extracting code in [14354/trunk/trac/env.py]. Under which conditions would get_pkginfo(core).get('version') return None for the Trac package?

[Ryan J Ollos]

In [14405], name attribute added to dictionary returned by get_pkginfo.

Other changes committed to 1.0-stable in [14406,14408:14409], merged to trunk in [14407,14410].