[PATCH] tests: add run-tests --changed option for running tests changed in revisions

[Jordi Gutiérrez Hermoso]

# HG changeset patch
# User Mads Kiilerich <madski at unity3d.com>
# Date 1393549740 -3600
#      Fri Feb 28 02:09:00 2014 +0100
# Node ID 3d1d16b19e7dd5e96e242daed86512429bc1d3f6
# Parent  f8e531a3a77cfe8aca930e60e66b5c25122a689e
tests: add run-tests --changed option for running tests changed in revisions

Convenient when polishing patches and changing details of how they change test
output.

This will probably break in weird ways for revsets with special quoting ... but
it is good enough for run-tests.

Usage example:
  yes | ./run-tests.py -li --changed qparent

diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -141,6 +141,8 @@
         help="skip tests listed in the specified blacklist file")
     parser.add_option("--whitelist", action="append",
         help="always run tests listed in the specified whitelist file")
+    parser.add_option("--changed", type="string",
+        help="run tests that are changed in parent rev or working directory")
     parser.add_option("-C", "--annotate", action="store_true",
         help="output files annotated with coverage")
     parser.add_option("-c", "--cover", action="store_true",
@@ -1181,7 +1183,13 @@
     checktools()
 
     if not args:
-        args = os.listdir(".")
+        if options.changed:
+            proc = Popen4('hg st --rev "%s" -man0 .' % options.changed,
+                          None, 0)
+            stdout, stderr = proc.communicate()
+            args = stdout.strip('\0').split('\0')
+        else:
+            args = os.listdir(".")
 
     tests = [t for t in args
              if t.startswith("test-")