Index: setup.py
===================================================================
--- setup.py	(revision 42536)
+++ setup.py	(working copy)
@@ -448,22 +448,41 @@
 
         # readline
         if self.compiler.find_library_file(lib_dirs, 'readline'):
-            readline_libs = ['readline']
-            if self.compiler.find_library_file(lib_dirs,
-                                                 'ncursesw'):
-                readline_libs.append('ncursesw')
-            elif self.compiler.find_library_file(lib_dirs,
-                                                 'ncurses'):
-                readline_libs.append('ncurses')
-            elif self.compiler.find_library_file(lib_dirs, 'curses'):
-                readline_libs.append('curses')
-            elif self.compiler.find_library_file(lib_dirs +
-                                               ['/usr/lib/termcap'],
-                                               'termcap'):
-                readline_libs.append('termcap')
-            exts.append( Extension('readline', ['readline.c'],
-                                   library_dirs=['/usr/lib/termcap'],
-                                   libraries=readline_libs) )
+            # This extra compilation helps identify incomplete
+            # implementations like BSD's libedit masquerading as readline.
+            # Unfortunately, I don't think distutils has clean
+            # symbol-finding routines like configure.  Maybe this will
+            # motivate someone to implement something or prove me wrong and
+            # correct this code...
+            hist_inc = find_file('history.h', [], inc_dirs)
+            have_hist = False
+            if hist_inc:
+                for hist_dir in hist_inc:
+                    hist_file = os.path.join(hist_dir, 'history.h')
+                    have_hist = ("history_truncate_file" in
+                                 open(hist_file).read())
+                    if have_hist:
+                        break
+            if have_hist:
+                readline_libs = ['readline']
+                if self.compiler.find_library_file(lib_dirs,
+                                                     'ncursesw'):
+                    readline_libs.append('ncursesw')
+                elif self.compiler.find_library_file(lib_dirs,
+                                                     'ncurses'):
+                    readline_libs.append('ncurses')
+                elif self.compiler.find_library_file(lib_dirs, 'curses'):
+                    readline_libs.append('curses')
+                elif self.compiler.find_library_file(lib_dirs +
+                                                   ['/usr/lib/termcap'],
+                                                   'termcap'):
+                    readline_libs.append('termcap')
+                exts.append( Extension('readline', ['readline.c'],
+                                       library_dirs=['/usr/lib/termcap'],
+                                       libraries=readline_libs) )
+            else:
+                print "*** incomplete readline detected ***"
+
         if platform not in ['mac']:
             # crypt module.