Merge ~cjwatson/launchpad:fix-miscompiled-pofile-query into launchpad:master

[Colin Watson]

Fix miscompiled query in POFileMixin._getTranslationSearchQuery

Converting POFile queries to Storm (https://code.launchpad.net/~cjwatson/launchpad/+git/launchpad/+merge/394702) introduced a serious performance regression. It turns out that using Reference objects via ClassAlias doesn't work as expected. The following:

    tm_ids = ClassAlias(TranslationMessage, "tm_ids")
    tm_ids.language == pofile.language

... is compiled to "TranslationMessage.language = $ID" rather than "tm_ids.language = $ID". Using the Reference's Int partner instead works around this.

I haven't worked out how to test this automatically (or even whether it results in a different set of rows rather than merely a much slower query), but I've manually tested on staging that the modified query performs reasonably again.

[Thiago F. Pappacena (pappacena)]

LGTM. Good catch!

review: Approve

diff --git a/lib/lp/translations/model/pofile.py b/lib/lp/translations/model/pofile.py
index b6af3e7..799eb18 100644
--- a/lib/lp/translations/model/pofile.py
+++ b/lib/lp/translations/model/pofile.py
@@ -189,13 +189,13 @@ class POFileMixIn(RosettaStats):
                                 tm_ids,
                                 Join(
                                     TranslationTemplateItem,
-                                    tm_ids.potmsgset ==
+                                    tm_ids.potmsgsetID ==
                                         TranslationTemplateItem.potmsgsetID)),
                             where=And(
                                 TranslationTemplateItem.potemplate ==
                                     pofile.potemplate,
                                 TranslationTemplateItem.sequence > 0,
-                                tm_ids.language == pofile.language),
+                                tm_ids.languageID == pofile.languageID),
                             distinct=True)),
                         Like(
                             POTranslation.translation,