Introduce new attribute (collapse_alternatives) to allow HTML in

multipart/alternative message after content filtering.

6 files changed, 25 insertions, 7 deletions

diff --git a/Mailman/Defaults.py.in b/Mailman/Defaults.py.in
index dd73fc4e..f1c09b81 100644
--- a/Mailman/Defaults.py.in
+++ b/Mailman/Defaults.py.in
@@ -985,6 +985,9 @@ DEFAULT_FILTER_FILENAME_EXTENSIONS = [
 # passed through. Format is the same as DEFAULT_FILTER_FILENAME_EXTENSIONS.
 DEFAULT_PASS_FILENAME_EXTENSIONS = []
 
+# Replace multipart/alternative with its first alternative.
+DEFAULT_COLLAPSE_ALTERNATIVES = Yes
+
 # Whether text/html should be converted to text/plain after content filtering
 # is performed.  Conversion is done according to HTML_TO_PLAIN_TEXT_COMMAND
 DEFAULT_CONVERT_HTML_TO_PLAINTEXT = Yes
diff --git a/Mailman/Gui/ContentFilter.py b/Mailman/Gui/ContentFilter.py
index d681d6df..401ecf9f 100644
--- a/Mailman/Gui/ContentFilter.py
+++ b/Mailman/Gui/ContentFilter.py
@@ -57,9 +57,13 @@ class ContentFilter(GUIBase):
             <p>After this initial filtering, any <tt>multipart</tt>
             attachments that are empty are removed.  If the outer message is
             left empty after this filtering, then the whole message is
-            discarded.  Then, each <tt>multipart/alternative</tt> section will
+            discarded.
+
+            <p> Then, each <tt>multipart/alternative</tt> section will
             be replaced by just the first alternative that is non-empty after
-            filtering.
+            filtering if
+            <a href="?VARHELP=contentfilter/collapse_alternatives"
+            >collapse_alternatives</a> is enabled.
 
             <p>Finally, any <tt>text/html</tt> parts that are left in the
             message may be converted to <tt>text/plain</tt> if
@@ -109,6 +113,10 @@ class ContentFilter(GUIBase):
              filename extension.  Leave this field blank to skip this filter
              test."""),),
 
+            ('collapse_alternatives', mm_cfg.Radio, (_('No'), _('Yes')), 0,
+             _("""Should Mailman collapse multipart/alternative to its
+             first part content?""")),
+
             ('convert_html_to_plaintext', mm_cfg.Radio, (_('No'), _('Yes')), 0,
              _("""Should Mailman convert <tt>text/html</tt> parts to plain
              text?  This conversion happens after MIME attachments have been
diff --git a/Mailman/Handlers/MimeDel.py b/Mailman/Handlers/MimeDel.py
index 79efa620..3afdce95 100644
--- a/Mailman/Handlers/MimeDel.py
+++ b/Mailman/Handlers/MimeDel.py
@@ -90,10 +90,12 @@ def process(mlist, msg, msgdata):
     # headers.  For now we'll move the subpart's payload into the outer part,
     # and then copy over its Content-Type: and Content-Transfer-Encoding:
     # headers (any others?).
-    collapse_multipart_alternatives(msg)
-    if ctype == 'multipart/alternative':
-        firstalt = msg.get_payload(0)
-        reset_payload(msg, firstalt)
+    # TK: Make this configurable from Gui/ContentFilter.py.
+    if mlist.collapse_alternatives:
+        collapse_multipart_alternatives(msg)
+        if ctype == 'multipart/alternative':
+            firstalt = msg.get_payload(0)
+            reset_payload(msg, firstalt)
     # If we removed some parts, make note of this
     changedp = 0
     if numparts <> len([subpart for subpart in msg.walk()]):
diff --git a/Mailman/MailList.py b/Mailman/MailList.py
index 8146f2a4..b369769f 100644
--- a/Mailman/MailList.py
+++ b/Mailman/MailList.py
@@ -363,6 +363,7 @@ class MailList(HTMLFormatter, Deliverer, ListAdmin,
             mm_cfg.DEFAULT_FILTER_FILENAME_EXTENSIONS
         self.pass_filename_extensions = mm_cfg.DEFAULT_PASS_FILENAME_EXTENSIONS
         self.filter_content = mm_cfg.DEFAULT_FILTER_CONTENT
+        self.collapse_alternatives = mm_cfg.DEFAULT_COLLAPSE_ALTERNATIVES
         self.convert_html_to_plaintext = \
             mm_cfg.DEFAULT_CONVERT_HTML_TO_PLAINTEXT
         self.filter_action = mm_cfg.DEFAULT_FILTER_ACTION
diff --git a/Mailman/Version.py b/Mailman/Version.py
index d8d69edc..2e123f25 100644
--- a/Mailman/Version.py
+++ b/Mailman/Version.py
@@ -36,7 +36,7 @@ HEX_VERSION = ((MAJOR_REV << 24) | (MINOR_REV << 16) | (MICRO_REV << 8) |
                (REL_LEVEL << 4)  | (REL_SERIAL << 0))
 
 # config.pck schema version number
-DATA_FILE_VERSION = 95
+DATA_FILE_VERSION = 96
 
 # qfile/*.db schema version number
 QFILE_SCHEMA_VERSION = 3
diff --git a/Mailman/versions.py b/Mailman/versions.py
index c7710b18..084a548f 100644
--- a/Mailman/versions.py
+++ b/Mailman/versions.py
@@ -403,6 +403,10 @@ def NewVars(l):
     # automatic discard
     add_only_if_missing('max_days_to_hold', 0)
     add_only_if_missing('nonmember_rejection_notice', '')
+    # multipart/alternative collapse
+    add_only_if_missing('collapse_alternatives', 
+        mm_cfg.DEFAULT_COLLAPSE_ALTERNATIVES)
+