testUpgradeInstanceWithOldDataFs: change connection string in Data.fs

This test loads a reference Data.fs, but we don't want to connect to
the mysql referenced in the mariadb, because it might be used by another
test node.

Before the beginning of the test, rewrite the connection string to the
one this test node is using.

This relies on an updated dump produced in nexedi/erp5-bin@8310e4e4

See merge request !1098

product/ERP5Type/tests/ERP5TypeTestSuite.py

@@ -19,8 +19,10 @@ class ERP5TypeTestSuite(TestSuite):
     return self.runUnitTest(test)
 
   def runUnitTest(self, *args, **kw):
+    instance_home = self.instance and 'unit_test.%u' % self.instance \
+                                   or 'unit_test'
     if self.instance:
-      args = ('--instance_home=unit_test.%u' % self.instance,) + args
+      args = ('--instance_home=' + instance_home, ) + args
     if self.__dict__.has_key("bt5_path"):
       args = ("--bt5_path=%s" % self.bt5_path,) + args
     instance_number = self.instance or 1
@@ -41,6 +43,18 @@ class ERP5TypeTestSuite(TestSuite):
       args = ("--firefox_bin=%s" % firefox_bin,) + args
     if xvfb_bin:
       args = ("--xvfb_bin=%s" % xvfb_bin,) + args
+    if 'testUpgradeInstanceWithOldDataFs' in args:
+      # our reference Data.fs uses `CONNECTION_STRING_REPLACED_BY_TEST_INIT_______________________________`
+      # as a connection string. Before we start, replace this by the connection string
+      # that this test node is using.
+      marker_connection_string = b'CONNECTION_STRING_REPLACED_BY_TEST_INIT_______________________________'
+      actual_connection_string = mysql_db_list[0].ljust(len(marker_connection_string)).encode()
+      assert len(marker_connection_string) == len(actual_connection_string)
+      with open(os.path.join(instance_home, 'var', 'Data.fs'), 'rb') as f:
+        data_fs = f.read()
+      with open(os.path.join(instance_home, 'var', 'Data.fs'), 'wb') as f:
+        f.write(data_fs.replace(marker_connection_string, actual_connection_string))
+
     try:
       runUnitTest = os.environ.get('RUN_UNIT_TEST',
                                    'runUnitTest')