Merge pull request #4877 from edx/dhm/course_id_pattern

Rewrite course url matcher to not be greedy

lms/envs/common.py

@@ -410,8 +410,12 @@ LMS_MIGRATION_ALLOWED_IPS = []
 
 # These are standard regexes for pulling out info like course_ids, usage_ids, etc.
 # They are used so that URLs with deprecated-format strings still work.
-COURSE_ID_PATTERN = r'(?P<course_id>(?:[^/]+/[^/]+/[^/]+)|(?:[^/]+))'
-COURSE_KEY_PATTERN = r'(?P<course_key_string>(?:[^/]+/[^/]+/[^/]+)|(?:[^/]+))'
+# Note: these intentionally greedily grab all chars up to the next slash including any pluses
+# DHM: I really wanted to ensure the separators were the same (+ or /) but all patts I tried had
+# too many inadvertent side effects :-(
+COURSE_KEY_PATTERN = r'(?P<course_key_string>[^/+]+(/|\+)[^/+]+(/|\+)[^/]+)'
+COURSE_ID_PATTERN = COURSE_KEY_PATTERN.replace('course_key_string', 'course_id')
+
 USAGE_KEY_PATTERN = r'(?P<usage_key_string>(?:i4x://?[^/]+/[^/]+/[^/]+/[^@]+(?:@[^/]+)?)|(?:[^/]+))'
 ASSET_KEY_PATTERN = r'(?P<asset_key_string>(?:/?c4x(:/)?/[^/]+/[^/]+/[^/]+/[^@]+(?:@[^/]+)?)|(?:[^/]+))'
 USAGE_ID_PATTERN = r'(?P<usage_id>(?:i4x://?[^/]+/[^/]+/[^/]+/[^@]+(?:@[^/]+)?)|(?:[^/]+))'