Index: build/run_tests.py
===================================================================
--- build/run_tests.py	(revision 1463012)
+++ build/run_tests.py	(working copy)
@@ -100,6 +100,11 @@ def _get_term_width():
       os.close(fd)
     except:
       pass
+  ## Some terminals (eg emacs *shell*, emacs *compilation*)
+  ## seem to return (0,0) from ioctl_GWINSZ, so let's deal
+  ## with that case...
+  if cr == (0, 0):
+    cr = None
   if not cr:
     try:
       cr = (os.environ['LINES'], os.environ['COLUMNS'])
@@ -178,7 +183,8 @@ class TestHarness:
     self.log = None
     self.ssl_cert = ssl_cert
     self.http_proxy = http_proxy
-    if not sys.stdout.isatty() or sys.platform == 'win32':
+    if not sys.stdout.isatty() or sys.platform == 'win32' or \
+           os.getenv("TERM") == "dumb":
       TextColors.disable()
 
   def run(self, list):
@@ -186,8 +192,9 @@ class TestHarness:
        there is a log file. Return zero iff all test programs passed.'''
     self._open_log('w')
     failed = 0
+    line_length = _get_term_width()
     for cnt, prog in enumerate(list):
-      failed = self._run_test(prog, cnt, len(list)) or failed
+      failed = self._run_test(prog, cnt, len(list), line_length) or failed
 
     if self.log is None:
       return failed
@@ -550,7 +557,7 @@ class TestHarness:
 
     return failed
 
-  def _run_test(self, prog, test_nr, total_tests):
+  def _run_test(self, prog, test_nr, total_tests, line_length):
     "Run a single test. Return the test's exit code."
 
     if self.log:
@@ -587,7 +594,6 @@ class TestHarness:
 
     progabs = os.path.abspath(os.path.join(self.srcdir, prog))
     old_cwd = os.getcwd()
-    line_length = _get_term_width()
     dots_needed = line_length \
                     - len(test_info) \
                     - len('success')