Combine can now ignore errors.

4 files changed, 45 insertions, 10 deletions

diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index 2802948e..6f5719fd 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -58,6 +58,10 @@ class Opts(object):
         '-i', '--ignore-errors', action='store_true',
         help="Ignore errors while reading source files.",
     )
+    ignore_combine_errors = optparse.make_option(
+        '-i', '--ignore-errors', action='store_true',
+        help="Ignore errors while reading data files.",
+    )
     include = optparse.make_option(
         '', '--include', action='store',
         metavar="PAT1,PAT2,...",
@@ -265,7 +269,10 @@ CMDS = {
     ),
 
     'combine': CmdOptionParser(
-        "combine", GLOBAL_ARGS,
+        "combine",
+        [
+            Opts.ignore_combine_errors,
+            ] + GLOBAL_ARGS,
         usage="<path1> <path2> ... <pathN>",
         description=(
             "Combine data from multiple coverage files collected "
@@ -464,7 +471,7 @@ class CoverageScript(object):
         elif options.action == "combine":
             self.coverage.load()
             data_dirs = args or None
-            self.coverage.combine(data_dirs)
+            self.coverage.combine(data_dirs, ignore_errors=options.ignore_errors)
             self.coverage.save()
             return OK
 
diff --git a/coverage/config.py b/coverage/config.py
index 458d4903..8aff41dc 100644
--- a/coverage/config.py
+++ b/coverage/config.py
@@ -162,6 +162,9 @@ class CoverageConfig(object):
         self.source = None
         self.timid = False
 
+        # Defaults for [combine]
+        self.ignore_combine_errors = False
+
         # Defaults for [report]
         self.exclude_list = DEFAULT_EXCLUDE[:]
         self.fail_under = 0
@@ -277,6 +280,9 @@ class CoverageConfig(object):
         ('source', 'run:source', 'list'),
         ('timid', 'run:timid', 'boolean'),
 
+        # [combine]
+        ('ignore_combine_errors', 'combine:ignore_errors', 'boolean'),
+
         # [report]
         ('exclude_list', 'report:exclude_lines', 'regexlist'),
         ('fail_under', 'report:fail_under', 'int'),
diff --git a/coverage/control.py b/coverage/control.py
index 16b09c84..77737181 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -279,7 +279,7 @@ class Coverage(object):
         # data file will be written into the directory where the process
         # started rather than wherever the process eventually chdir'd to.
         self.data = CoverageData(debug=self.debug)
-        self.data_files = CoverageDataFiles(basename=self.config.data_file)
+        self.data_files = CoverageDataFiles(basename=self.config.data_file, warn=self._warn)
 
         # The directories for files considered "installed with the interpreter".
         self.pylib_dirs = set()
@@ -757,7 +757,7 @@ class Coverage(object):
         self.get_data()
         self.data_files.write(self.data, suffix=self.data_suffix)
 
-    def combine(self, data_paths=None):
+    def combine(self, data_paths=None, ignore_errors=None):
         """Combine together a number of similarly-named coverage data files.
 
         All coverage data files whose name starts with `data_file` (from the
@@ -776,6 +776,8 @@ class Coverage(object):
         self._init()
         self.get_data()
 
+        self.config.from_args(ignore_combine_errors=ignore_errors)
+
         aliases = None
         if self.config.paths:
             aliases = PathAliases()
@@ -784,7 +786,12 @@ 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_paths)
+        self.data_files.combine_parallel_data(
+            self.data,
+            aliases=aliases,
+            data_paths=data_paths,
+            ignore_errors=self.config.ignore_combine_errors,
+        )
 
     def get_data(self):
         """Get the collected data and reset the collector.
diff --git a/coverage/data.py b/coverage/data.py
index c608f489..b8d9dadf 100644
--- a/coverage/data.py
+++ b/coverage/data.py
@@ -601,12 +601,15 @@ class CoverageData(object):
 class CoverageDataFiles(object):
     """Manage the use of coverage data files."""
 
-    def __init__(self, basename=None):
+    def __init__(self, basename=None, warn=None):
         """Create a CoverageDataFiles to manage data files.
 
+        `warn` is the warning function to use.
+
         `basename` is the name of the file to use for storing data.
 
         """
+        self.warn = warn
         # Construct the file name that will be used for data storage.
         self.filename = os.path.abspath(basename or ".coverage")
 
@@ -659,7 +662,7 @@ class CoverageDataFiles(object):
             filename += "." + suffix
         data.write_file(filename)
 
-    def combine_parallel_data(self, data, aliases=None, data_paths=None):
+    def combine_parallel_data(self, data, aliases=None, data_paths=None, ignore_errors=False):
         """Combine a number of data files together.
 
         Treat `self.filename` as a file prefix, and combine the data from all
@@ -677,6 +680,9 @@ class CoverageDataFiles(object):
 
         Every data file found and combined is then deleted from disk.
 
+        If `ignore_errors` is True, then files that cannot be read will cause
+        a warning, and will not be deleted.
+
         """
         # Because of the os.path.abspath in the constructor, data_dir will
         # never be an empty string.
@@ -696,9 +702,18 @@ class CoverageDataFiles(object):
 
         for f in files_to_combine:
             new_data = CoverageData()
-            new_data.read_file(f)
-            data.update(new_data, aliases=aliases)
-            file_be_gone(f)
+            try:
+                new_data.read_file(f)
+            except CoverageException as exc:
+                if not ignore_errors:
+                    raise
+                if self.warn:
+                    # The CoverageException has the file name in it, so just
+                    # use the message as the warning.
+                    self.warn(str(exc))
+            else:
+                data.update(new_data, aliases=aliases)
+                file_be_gone(f)
 
 
 def canonicalize_json_data(data):