Update docstring and command line help text.

--HG--
branch : combine-from-multiple-dirs

2 files changed, 8 insertions, 1 deletions

diff --git a/coverage/cmdline.py b/coverage/cmdline.py
index c611e037..66a76fa6 100644
--- a/coverage/cmdline.py
+++ b/coverage/cmdline.py
@@ -252,7 +252,10 @@ CMDS = {
         usage = "<dir1> <dir2> ... <dirN>",
         description = "Combine data from multiple coverage files collected "
             "with 'run -p'.  The combined results are written to a single "
-            "file representing the union of the data."
+            "file representing the union of the data. The positional "
+            "arguments are directories from which the data files should be "
+            "combined. By default, only data files in the current directory "
+            "are combined."
         ),
 
     'debug': CmdOptionParser("debug", GLOBAL_ARGS,
diff --git a/coverage/control.py b/coverage/control.py
index 4a9ac727..2c8d384e 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -724,6 +724,10 @@ class Coverage(object):
         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.
+
         """
         self._init()
         aliases = None