db upgrades broken

[Dave Abrahams <dave@…>]

I was upgrading from to r5468 to r5748 and got this:

Command failed: iteration over non-sequence

with no backtrace! Had to somehow divine that trac-admin is run through trac/admin/console.py (the body of trac-admin gives no clue) and comment out the exception handler to debug this. The following patch fixes it:

trac/upgrades/db21.py

@@ -3 +3 @@
     """Upgrade the reports to better handle the new workflow capabilities"""                                                                                                                        
     db = env.get_db_cnx()                                                                                                                                                                           
     owner = db.concat('owner', "' *'")                                                                                                                                                              
-    reports = list(cursor.execute('SELECT id, query, description FROM report'))                                                                                                                     
+    reports = list(cursor.execute('SELECT id, query, description FROM report')                                                                                                                      
+                   or ())                                                                                                                                                                           
     for report, query, description in reports:                                                                                                                                                      
         # All states other than 'closed' are "active".                                                                                                                                              
         query = query.replace("IN ('new', 'assigned', 'reopened')",                                                                                                                                 

[Christian Boos]

#5575 was closed as duplicate. I've closed it in favor of this one, as there was a patch here.

But upon further examination, the patch is not correct, as the return value of cursor.execute is not specified (see ​PEP:0249), and used to be None (see ​PEP:0248).

So I'll use fetchall instead.

[Christian Boos]

Fixed in r5756.