Get --append working again.

3 files changed, 9 insertions, 10 deletions

diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index a6ae7c3f..ee239b2d 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -577,10 +577,7 @@ class CoverageScript(object):
             self.coverage.stop()
             if code_ran:
                 if options.append:
-                    from coverage.data import CoverageData
-                    old_data = CoverageData()
-                    old_data.read_file(self.coverage.config.data_file)
-                    self.coverage.data.update(old_data)
+                    self.coverage.combine(data_paths=[self.coverage.config.data_file])
                 self.coverage.save()
 
             # Restore the old path
diff --git a/coverage/control.py b/coverage/control.py
index deeeae45..8e51c2c0 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -708,19 +708,21 @@ class Coverage(object):
         self.get_data()
         self.data_files.write(self.data, suffix=self.data_suffix)
 
-    def combine(self, data_dirs=None):
+    def combine(self, data_paths=None):
         """Combine together a number of similarly-named coverage data files.
 
         All coverage data files whose name starts with `data_file` (from the
         coverage() constructor) will be read, and combined together into the
         current measurements.
 
-        `data_dirs` is a list of directories from which data files should be
-        combined. If no list is passed, then the data files from the current
-        directory will be combined.
+        `data_paths` is a list of files or directories from which data should
+        be combined. If no list is passed, then the data files from the
+        directory indicated by the current data file (probably the current
+        directory) will be combined.
 
         """
         self._init()
+        self.get_data()
 
         aliases = None
         if self.config.paths:
@@ -730,7 +732,7 @@ class Coverage(object):
                 for pattern in paths[1:]:
                     aliases.add(pattern, result)
 
-        self.data_files.combine_parallel_data(self.data, aliases=aliases, data_paths=data_dirs)
+        self.data_files.combine_parallel_data(self.data, aliases=aliases, data_paths=data_paths)
 
     def get_data(self):
         """Get the collected data and reset the collector.
diff --git a/tests/test_cmdline.py b/tests/test_cmdline.py
index cbc44efb..20444715 100644
--- a/tests/test_cmdline.py
+++ b/tests/test_cmdline.py
@@ -350,10 +350,10 @@ class CmdLineTest(BaseCmdLineTest):
         # run -a calls coverage.load first without erasing.
         self.cmd_executes("run -a foo.py", """\
             .coverage()
-            .load()
             .start()
             .run_python_file('foo.py', ['foo.py'])
             .stop()
+            .combine(data_paths=['.coverage'])
             .save()
             """)
         # --timid sets a flag, and program arguments get passed through.