Revert regression from r81256 (with release manager approval, see #8688)

1 files changed, 59 insertions, 27 deletions

diff --git a/Lib/distutils/command/sdist.py b/Lib/distutils/command/sdist.py
index 535b8d2..a366d1e 100644
--- a/Lib/distutils/command/sdist.py
+++ b/Lib/distutils/command/sdist.py
@@ -57,8 +57,7 @@ class sdist (Command):
          "just regenerate the manifest and then stop "
          "(implies --force-manifest)"),
         ('force-manifest', 'f',
-         "forcibly regenerate the manifest and carry on as usual. "
-         "Deprecated: now the manifest is always regenerated."),
+         "forcibly regenerate the manifest and carry on as usual"),
         ('formats=', None,
          "formats for source distribution (comma-separated list)"),
         ('keep-temp', 'k',
@@ -191,34 +190,67 @@ class sdist (Command):
         distribution, and put it in 'self.filelist'.  This might involve
         reading the manifest template (and writing the manifest), or just
         reading the manifest, or just using the default file set -- it all
-        depends on the user's options.
+        depends on the user's options and the state of the filesystem.
         """
-        # new behavior:
-        # the file list is recalculated everytime because
-        # even if MANIFEST.in or setup.py are not changed
-        # the user might have added some files in the tree that
-        # need to be included.
-        #
-        #  This makes --force the default and only behavior.
-        template_exists = os.path.isfile(self.template)
-        if not template_exists:
-            self.warn(("manifest template '%s' does not exist " +
-                        "(using default file list)") %
-                        self.template)
-        self.filelist.findall()
-
-        if self.use_defaults:
-            self.add_defaults()
 
+        # If we have a manifest template, see if it's newer than the
+        # manifest; if so, we'll regenerate the manifest.
+        template_exists = os.path.isfile(self.template)
         if template_exists:
-            self.read_template()
-
-        if self.prune:
-            self.prune_file_list()
-
-        self.filelist.sort()
-        self.filelist.remove_duplicates()
-        self.write_manifest()
+            template_newer = dep_util.newer(self.template, self.manifest)
+
+        # The contents of the manifest file almost certainly depend on the
+        # setup script as well as the manifest template -- so if the setup
+        # script is newer than the manifest, we'll regenerate the manifest
+        # from the template.  (Well, not quite: if we already have a
+        # manifest, but there's no template -- which will happen if the
+        # developer elects to generate a manifest some other way -- then we
+        # can't regenerate the manifest, so we don't.)
+        self.debug_print("checking if %s newer than %s" %
+                         (self.distribution.script_name, self.manifest))
+        setup_newer = dep_util.newer(self.distribution.script_name,
+                                     self.manifest)
+
+        # cases:
+        #   1) no manifest, template exists: generate manifest
+        #      (covered by 2a: no manifest == template newer)
+        #   2) manifest & template exist:
+        #      2a) template or setup script newer than manifest:
+        #          regenerate manifest
+        #      2b) manifest newer than both:
+        #          do nothing (unless --force or --manifest-only)
+        #   3) manifest exists, no template:
+        #      do nothing (unless --force or --manifest-only)
+        #   4) no manifest, no template: generate w/ warning ("defaults only")
+
+        manifest_outofdate = (template_exists and
+                              (template_newer or setup_newer))
+        force_regen = self.force_manifest or self.manifest_only
+        manifest_exists = os.path.isfile(self.manifest)
+        neither_exists = (not template_exists and not manifest_exists)
+
+        # Regenerate the manifest if necessary (or if explicitly told to)
+        if manifest_outofdate or neither_exists or force_regen:
+            if not template_exists:
+                self.warn(("manifest template '%s' does not exist " +
+                           "(using default file list)") %
+                          self.template)
+            self.filelist.findall()
+
+            if self.use_defaults:
+                self.add_defaults()
+            if template_exists:
+                self.read_template()
+            if self.prune:
+                self.prune_file_list()
+
+            self.filelist.sort()
+            self.filelist.remove_duplicates()
+            self.write_manifest()
+
+        # Don't regenerate the manifest, just read it in.
+        else:
+            self.read_manifest()
 
     # get_file_list ()