# Description: do not overwrite <mailbox>_archive.gz when it is a symbolic link
# Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=349068
# Author: Serafeim Zanikolas <serzan@hellug.gr>
# Last-Update: 2009-02-22
Index: archivemail/archivemail
===================================================================
--- archivemail.orig/archivemail	2008-08-15 21:41:37.000000000 +0100
+++ archivemail/archivemail	2008-08-15 22:00:20.000000000 +0100
@@ -487,6 +487,20 @@
         """Return the current size of the mbox file"""
         return os.path.getsize(self.mbox_file_name)
 
+    def get_link_target(self, file_name):
+        """Return the supplied file name if not a link; else its target."""
+        if not os.path.islink(file_name):
+            return file_name
+        orig_file_name = prev = file_name
+        while os.path.islink(file_name):
+            prev = file_name
+            file_name = os.readlink(file_name)
+        if not os.path.isabs(file_name):
+            file_name = os.path.abspath(os.path.join(os.path.dirname(prev),
+                                                     file_name))
+        if not os.path.exists(file_name):
+            unexpected_error("%s is a broken symbolic link" % orig_file_name)
+        return file_name
 
 class RetainMbox(Mbox):
     """Class for holding messages that will be retained from the original
@@ -525,6 +539,7 @@
         mode =  os.stat(self.__final_name)[stat.ST_MODE]
         os.chmod(self.mbox_file_name, mode)
 
+        self.__final_name = self.get_link_target(self.__final_name)
         vprint("renaming '%s' to '%s'" % (self.mbox_file_name, self.__final_name))
         try:
             os.rename(self.mbox_file_name, self.__final_name)
@@ -615,6 +630,7 @@
         final_name = self.__final_name
         if not options.no_compress:
             final_name = final_name + ".gz"
+        final_name = self.get_link_target(final_name)
         vprint("renaming '%s' to '%s'" % (self.mbox_file_name, 
             final_name))
         try:
@@ -1145,9 +1161,6 @@
         tempfile.tempdir = new_temp_dir
         vprint("set tempfile directory to '%s'" % new_temp_dir)
 
-        if os.path.islink(mailbox_name):
-            unexpected_error("'%s' is a symbolic link -- I feel nervous!" % 
-                mailbox_name)
         if imap_scheme == 'imap' or imap_scheme == 'imaps':
             vprint("guessing mailbox is of type: imap(s)")
             _archive_imap(mailbox_name, final_archive_name)
Index: archivemail/test_archivemail.py
===================================================================
--- archivemail.orig/test_archivemail.py	2008-08-15 21:40:56.000000000 +0100
+++ archivemail/test_archivemail.py	2008-08-15 21:59:10.000000000 +0100
@@ -99,6 +99,37 @@
 
 ############ Mbox Class testing ##############
 
+class TestMboxSymLinkResolution(TestCaseInTempdir):
+    def setUp(self):
+        super(TestMboxSymLinkResolution, self).setUp()
+        self.mbox_file_name = make_mbox()
+        self.mbox = archivemail.Mbox(self.mbox_file_name)
+
+    def testAbsoluteSymlink(self):
+        """Resolve an absolute symlink in a different directory"""
+        link_name = "%s/symlink-to-mbox" % tempfile.mkdtemp()
+        os.symlink(self.mbox_file_name, link_name)
+        link_target = self.mbox.get_link_target(link_name)
+        self.assertEqual(self.mbox_file_name, link_target)
+
+    def testRelativeSymlink(self):
+        """Resolve a relative symlink in a different directory"""
+        link_dir = tempfile.mkdtemp()
+        link_name = "%s/symlink-to-mbox" % link_dir
+        run = "cd %s && ln -s ../%s %s" % (link_dir,\
+                os.path.basename(self.mbox_file_name),\
+                os.path.basename(link_name))
+        self.assertEqual(os.system(run), 0)
+        link_target = self.mbox.get_link_target(link_name)
+        self.assertEqual(self.mbox_file_name, link_target)
+
+    def testBrokenSymlink(self):
+        """Archive name that is a broken link should raise an error"""
+        link_name = "%s/symlink-to-mbox" % tempfile.mkdtemp()
+        os.symlink("%s-missing" % self.mbox_file_name, link_name)
+        self.assertRaises(archivemail.UnexpectedError,
+                self.mbox.get_link_target, link_name)
+
 class TestMboxIsEmpty(TestCaseInTempdir):
     def setUp(self):
         super(TestMboxIsEmpty, self).setUp()