=== modified file 'Mailman/Cgi/admindb.py'
--- Mailman/Cgi/admindb.py	2018-06-17 23:47:34 +0000
+++ Mailman/Cgi/admindb.py	2019-01-31 19:34:24 +0000
@@ -715,6 +715,8 @@
     chars = 0
     # A negative value means, include the entire message regardless of size
     limit = mm_cfg.ADMINDB_PAGE_TEXT_LIMIT
+    if mm_cfg.HOLD_MESSAGES_AS_PICKLES == 0:
+        limit = -1
     for line in email.Iterators.body_line_iterator(msg, decode=True):
         lines.append(line)
         chars += len(line)
@@ -787,12 +789,12 @@
     t.AddCellInfo(row, col-1, align='right')
     t.AddRow([Bold(_('Message Headers:')),
               TextArea('headers-%d' % id, hdrtxt,
-                       rows=EXCERPT_HEIGHT, cols=EXCERPT_WIDTH, readonly=1)])
+                       rows=EXCERPT_HEIGHT, cols=EXCERPT_WIDTH, readonly=0)])
     row, col = t.GetCurrentRowIndex(), t.GetCurrentCellIndex()
     t.AddCellInfo(row, col-1, align='right')
     t.AddRow([Bold(_('Message Excerpt:')),
               TextArea('fulltext-%d' % id, Utils.websafe(body),
-                       rows=EXCERPT_HEIGHT, cols=EXCERPT_WIDTH, readonly=1)])
+                       rows=EXCERPT_HEIGHT, cols=EXCERPT_WIDTH, readonly=0)])
     t.AddCellInfo(row+1, col-1, align='right')
     form.AddItem(t)
     form.AddItem('<p>')
@@ -914,6 +916,8 @@
             continue
         # Get the action comment and reasons if present.
         commentkey = 'comment-%d' % request_id
+        headerskey = 'headers-%d' % request_id
+        fulltextkey = 'fulltext-%d' % request_id
         preservekey = 'preserve-%d' % request_id
         forwardkey = 'forward-%d' % request_id
         forwardaddrkey = 'forward-addr-%d' % request_id
@@ -932,8 +936,14 @@
         preserve = 0
         forward = 0
         forwardaddr = ''
+        headers = ''
+        fulltext = ''
         if cgidata.has_key(commentkey):
             comment = cgidata[commentkey].value
+        if cgidata.has_key(headerskey):
+            headers = cgidata[headerskey].value
+        if cgidata.has_key(fulltextkey):
+            fulltext = cgidata[fulltextkey].value
         if cgidata.has_key(preservekey):
             preserve = cgidata[preservekey].value
         if cgidata.has_key(forwardkey):
@@ -951,7 +961,7 @@
         # Handle the request id
         try:
             mlist.HandleRequest(request_id, v, comment,
-                                preserve, forward, forwardaddr)
+                                preserve, forward, forwardaddr, headers, fulltext)
         except (KeyError, Errors.LostHeldMessage):
             # That's okay, it just means someone else has already updated the
             # database while we were staring at the page, so just ignore it

=== modified file 'Mailman/ListAdmin.py'
--- Mailman/ListAdmin.py	2018-06-18 11:35:51 +0000
+++ Mailman/ListAdmin.py	2019-01-31 19:22:32 +0000
@@ -44,6 +44,8 @@
 from Mailman.Logging.Syslog import syslog
 from Mailman import i18n
 
+import string
+
 _ = i18n._
 def D_(s):
     return s
@@ -161,12 +163,12 @@
         return type
 
     def HandleRequest(self, id, value, comment=None, preserve=None,
-                      forward=None, addr=None):
+                      forward=None, addr=None, headers=None, fulltext=None):
         self.__opendb()
         rtype, data = self.__db[id]
         if rtype == HELDMSG:
             status = self.__handlepost(data, value, comment, preserve,
-                                       forward, addr)
+                                       forward, addr, headers, fulltext)
         elif rtype == UNSUBSCRIPTION:
             status = self.__handleunsubscription(data, value, comment)
         else:
@@ -229,10 +231,36 @@
         self.__db[id] = (HELDMSG, data)
         return id
 
-    def __handlepost(self, record, value, comment, preserve, forward, addr):
+    def __handlepost(self, record, value, comment, preserve, forward, addr, headers, fulltext):
         # For backwards compatibility with pre 2.0beta3
         ptime, sender, subject, reason, filename, msgdata = record
         path = os.path.join(mm_cfg.DATA_DIR, filename)
+        # Handle editing - you must set HOLD_MESSAGES_AS_PICKLES = 0 in the config.
+        if (headers or fulltext) and not mm_cfg.HOLD_MESSAGES_AS_PICKLES:
+            # Read held message in
+            try:
+                fp = open(path)
+            except IOError, e:
+                if e.errno <> errno.ENOENT: raise
+                return LOST
+            try:
+                rawmsg = fp.read()
+            finally:
+                fp.close()
+            # Parse headers and body
+            parts = string.split(rawmsg,'\n\n')
+            if len(headers) == 0:
+                headers = parts[0]
+            if len(fulltext) == 0:
+                fulltext = parts[1]
+            rawmsg = headers + '\n\n' + fulltext
+            # Write it out again to held file
+            try:
+                fp = open(path, 'w')
+                fp.write(rawmsg)
+            finally:
+                if fp:
+                    fp.close()
         # Handle message preservation
         if preserve:
             parts = os.path.split(path)[1].split(DASH)