[checkupdates] update submodules according to tag

In case the version information is inside a submodule we need to
checkout the submodule at the version of the tag we test.

Found with org.courville.nova.

Closes: #622

fdroidserver/checkupdates.py

@@ -141,6 +141,7 @@ def check_tags(app, pattern):
     for tag in tags:
         logging.debug("Check tag: '{0}'".format(tag))
         vcs.gotorevision(tag)
+        try_init_submodules(app, last_build, vcs)
 
         if app.UpdateCheckData:
             filecode, codeex, filever, verex = app.UpdateCheckData.split('|')

tests/run-tests

@@ -1367,6 +1367,54 @@ $fdroid checkupdates --allow-dirty
 grep "CurrentVersionCode: 2" metadata/fake.yml
 
 
+#------------------------------------------------------------------------------#
+echo_header "checkupdates check version in submodule"
+
+ROOT=$(create_test_dir)
+cd "$ROOT"
+mkdir app sub
+cd sub
+$git init
+echo 1 > ver
+$git add ver
+$git commit -m 1
+
+cd ../app
+$git init
+$git submodule add "file://$(pwd)/../sub"
+$git commit -am 1
+$git tag 1
+
+cd ../sub
+echo 2 > ver
+$git commit -am 2
+
+cd ../app
+$git init
+$git submodule update --remote
+$git commit -am 2
+
+cd ..
+mkdir repo
+mkdir metadata
+cat > metadata/fake.yml <<EOF
+RepoType: git
+Repo: file://$(pwd)/app
+Builds:
+   - versionName: 0
+     versionCode: 0
+     submodules: true
+AutoUpdateMode: Version
+UpdateCheckMode: Tags
+UpdateCheckData: 'sub/ver|(\d)||'
+CurrentVersion: 0
+CurrentVersionCode: 0
+EOF
+
+$fdroid checkupdates --allow-dirty --auto -v
+grep "CurrentVersionCode: 1" metadata/fake.yml
+
+
 #------------------------------------------------------------------------------#
 
 # remove this to prevent git conflicts and complaining