Remove postcodes also from word table when they no longer exist

Also adds tests for postcode updates.

Fixes #1273.

test/bdd/db/import/postcodes.feature

@@ -125,3 +125,15 @@ Feature: Import of postcodes
         Then placex contains
             | object | postcode  |
             | W93    | 112 DE 34 |
+
+    Scenario: Postcodes are added to the postcode and word table
+        Given the places
+           | osm | class | type  | addr+postcode | addr+housenumber | geometry |
+           | N34 | place | house | 01982         | 111              |country:de |
+        When importing
+        Then location_postcode contains exactly
+           | country | postcode | geometry |
+           | de      | 01982    | country:de |
+        And word contains
+           | word  | class | type |
+           | 01982 | place | postcode |

test/bdd/db/update/postcode.feature

@@ -0,0 +1,58 @@
+@DB
+Feature: Update of postcode
+    Tests for updating of data related to postcodes
+
+    Scenario: A new postcode appears in the postcode and word table
+        Given the places
+           | osm | class | type  | addr+postcode | addr+housenumber | geometry |
+           | N34 | place | house | 01982         | 111              |country:de |
+        When importing
+        Then location_postcode contains exactly
+           | country | postcode | geometry |
+           | de      | 01982    | country:de |
+        When updating places
+           | osm | class | type  | addr+postcode | addr+housenumber | geometry |
+           | N35 | place | house | 4567          | 5                |country:ch |
+        And updating postcodes
+        Then location_postcode contains exactly
+           | country | postcode | geometry |
+           | de      | 01982    | country:de |
+           | ch      | 4567     | country:ch |
+        And word contains
+           | word  | class | type |
+           | 01982 | place | postcode |
+           | 4567  | place | postcode |
+
+     Scenario: When the last postcode is deleted, it is deleted from postcode and word
+        Given the places
+           | osm | class | type  | addr+postcode | addr+housenumber | geometry |
+           | N34 | place | house | 01982         | 111              |country:de |
+           | N35 | place | house | 4567          | 5                |country:ch |
+        When importing
+        And marking for delete N34
+        And updating postcodes
+        Then location_postcode contains exactly
+           | country | postcode | geometry |
+           | ch      | 4567     | country:ch |
+        And word contains not
+           | word  | class | type |
+           | 01982 | place | postcode |
+        And word contains
+           | word  | class | type |
+           | 4567  | place | postcode |
+
+     Scenario: A postcode is not deleted from postcode and word when it exist in another country
+        Given the places
+           | osm | class | type  | addr+postcode | addr+housenumber | geometry |
+           | N34 | place | house | 01982         | 111              |country:de |
+           | N35 | place | house | 01982         | 5                |country:ch |
+        When importing
+        And marking for delete N34
+        And updating postcodes
+        Then location_postcode contains exactly
+           | country | postcode | geometry |
+           | ch      | 01982    | country:ch |
+        And word contains
+           | word  | class | type |
+           | 01982 | place | postcode |
+

test/bdd/steps/db_ops.py

@@ -329,6 +329,10 @@ def update_place_table(context):
 
     check_database_integrity(context)
 
+@when("updating postcodes")
+def update_postcodes(context):
+    context.nominatim.run_update_script('calculate-postcodes')
+
 @when("marking for delete (?P<oids>.*)")
 def delete_places(context, oids):
     context.nominatim.run_setup_script(
@@ -477,6 +481,43 @@ def check_search_name_contents(context, exclude):
 
     context.db.commit()
 
+@then("location_postcode contains exactly")
+def check_location_postcode(context):
+    cur = context.db.cursor(cursor_factory=psycopg2.extras.DictCursor)
+
+    cur.execute("SELECT *, ST_AsText(geometry) as geomtxt FROM location_postcode")
+    eq_(cur.rowcount, len(list(context.table)),
+        "Postcode table has %d rows, expected %d rows."
+          % (cur.rowcount, len(list(context.table))))
+
+    table = list(cur)
+    for row in context.table:
+        for i in range(len(table)):
+            if table[i]['country_code'] != row['country'] \
+                    or table[i]['postcode'] != row['postcode']:
+                continue
+            for h in row.headings:
+                if h not in ('country', 'postcode'):
+                    assert_db_column(table[i], h, row[h], context)
+
+@then("word contains(?P<exclude> not)?")
+def check_word_table(context, exclude):
+    cur = context.db.cursor(cursor_factory=psycopg2.extras.DictCursor)
+
+    for row in context.table:
+        wheres = []
+        values = []
+        for h in row.headings:
+            wheres.append("%s = %%s" % h)
+            values.append(row[h])
+        cur.execute("SELECT * from word WHERE %s" % ' AND '.join(wheres), values)
+        if exclude:
+            eq_(0, cur.rowcount,
+                "Row still in word table: %s" % '/'.join(values))
+        else:
+            assert_greater(cur.rowcount, 0,
+                           "Row not in word table: %s" % '/'.join(values))
+
 @then("place_addressline contains")
 def check_place_addressline(context):
     cur = context.db.cursor(cursor_factory=psycopg2.extras.DictCursor)