Merge branch 'reinout-future-import-scripts' of...

Merge branch 'reinout-future-import-scripts' of https://github.com/reinout/buildout into reinout-reinout-future-import-scripts

src/zc/buildout/easy_install.py

@@ -1078,22 +1078,30 @@ def _distutils_script(path, dest, script_content, initialization, rsetup):
     if not ('#!' in lines[0]) and ('python' in lines[0]):
         # The script doesn't follow distutil's rules.  Ignore it.
         return []
-    source_encoding_line = ''
-    original_content = ''.join(lines[1:])
-    if (len(lines) > 1) and is_source_encoding_line(lines[1]):
-        # The second line contains a source encoding line. Copy it verbatim.
-        source_encoding_line = lines[1].rstrip()
-        original_content = ''.join(lines[2:])
+    lines = lines[1:]  # Strip off the first hashbang line.
+    line_with_first_import = len(lines)
+    for line_number, line in enumerate(lines):
+        if not 'import' in line:
+            continue
+        if not line.startswith('import') or line.startswith('from'):
+            continue
+        if '__future__' in line:
+            continue
+        line_with_first_import = line_number
+        break
+
+    before = ''.join(lines[:line_with_first_import])
+    after = ''.join(lines[line_with_first_import:])
 
     python = _safe_arg(sys.executable)
 
     contents = distutils_script_template % dict(
         python = python,
-        source_encoding_line = source_encoding_line,
         path = path,
         initialization = initialization,
         relative_paths_setup = rsetup,
-        original_content = original_content
+        before = before,
+        after = after
         )
     return _create_script(contents, dest)
 
@@ -1158,9 +1166,8 @@ if __name__ == '__main__':
     sys.exit(%(module_name)s.%(attrs)s(%(arguments)s))
 '''
 
-distutils_script_template = script_header + '''\
-
-%(source_encoding_line)s
+distutils_script_template = script_header + '''
+%(before)s
 %(relative_paths_setup)s
 import sys
 sys.path[0:0] = [
@@ -1168,7 +1175,7 @@ sys.path[0:0] = [
   ]
 %(initialization)s
 
-%(original_content)s'''
+%(after)s'''
 
 
 def _pyscript(path, dest, rsetup, initialization=''):

src/zc/buildout/easy_install.txt

@@ -962,12 +962,14 @@ It also works for zipped eggs:
 Distutils copies the script files verbatim, apart from a line at the top that
 looks like ``#!/usr/bin/python``, which gets replaced by the actual python
 interpreter. Buildout does the same, but additionally also adds the sys.path
-like for the console_scripts. Note that the second line in the scripts can
-contain a source encoding hint; buildout retains it.
+like for the console_scripts.
 
     >>> cat(distbin, 'distutilsscript')
     #!/usr/local/bin/python2.7
     # -*- coding: utf-8 -*-
+    """Module docstring."""
+    from __future__ import print_statement
+    <BLANKLINE>
     <BLANKLINE>
     import sys
     sys.path[0:0] = [
@@ -975,8 +977,15 @@ contain a source encoding hint; buildout retains it.
       ]
     <BLANKLINE>
     <BLANKLINE>
+    import os
     import sys; sys.stdout.write("distutils!\n")
 
+Note that there are several items that need to come first in such a script
+*before* buildout's ``sys.path`` statements: a source encoding hint, a module
+docstring and ``__future__`` imports. Buildout retains them in their proper
+place by looking at the first non-future import and placing its ``sys.path``
+statement before that.
+
 Due to the nature of distutils scripts, buildout cannot pass arguments as
 there's no specific method to pass them to.
 

src/zc/buildout/tests.py

@@ -2945,6 +2945,9 @@ def create_sample_eggs(test, executable=sys.executable):
             tmp, 'distutilsscript',
             '#!/usr/bin/python\n'
             '# -*- coding: utf-8 -*-\n'
+            '"""Module docstring."""\n'
+            'from __future__ import print_statement\n'
+            'import os\n'
             'import sys; sys.stdout.write("distutils!\\n")\n'
             )
         write(