[evolution] Bug 588833 - Improve account selection heuristics for replies

[Matthew Barnes <mbarnes src gnome org>]

commit 320ec4b32e74fa948f122868ba5474a81fad5875
Author: Matthew Barnes <mbarnes redhat com>
Date:   Thu Feb 18 17:31:34 2010 -0500

    Bug 588833 - Improve account selection heuristics for replies

 mail/em-utils.c |  133 ++++++++++++++++++++++++++++++++++++-------------------
 1 files changed, 88 insertions(+), 45 deletions(-)
---
diff --git a/mail/em-utils.c b/mail/em-utils.c
index a2a6705..d664a63 100644
--- a/mail/em-utils.c
+++ b/mail/em-utils.c
@@ -2167,77 +2167,120 @@ em_utils_generate_account_hash (void)
 }
 
 EAccount *
+em_utils_guess_account (CamelMimeMessage *message,
+                        CamelFolder *folder)
+{
+	EAccount *account = NULL;
+
+	g_return_val_if_fail (CAMEL_IS_MIME_MESSAGE (message), NULL);
+
+	if (folder != NULL)
+		g_return_val_if_fail (CAMEL_IS_FOLDER (folder), NULL);
+
+	/* check for newsgroup header */
+	if (folder != NULL
+	    && camel_medium_get_header (CAMEL_MEDIUM (message), "Newsgroups"))
+		account = guess_account_from_folder (folder);
+
+	/* check for source folder */
+	if (account == NULL && folder != NULL)
+		account = guess_account_from_folder (folder);
+
+	/* then message source */
+	if (account == NULL)
+		account = guess_account_from_message (message);
+
+	return account;
+}
+
+EAccount *
 em_utils_guess_account_with_recipients (CamelMimeMessage *message,
                                         CamelFolder *folder)
 {
-	GHashTable *account_hash = NULL;
 	EAccount *account = NULL;
-	GList *iter, *recipients = NULL;
+	EAccountList *account_list;
+	GHashTable *recipients;
+	EIterator *iter;
 	const CamelInternetAddress *addr;
 	const gchar *type;
+	const gchar *key;
+
+	/* This policy is subject to debate and tweaking,
+	 * but please also document the rational here. */
 
 	g_return_val_if_fail (CAMEL_IS_MIME_MESSAGE (message), NULL);
 
-	account = em_utils_guess_account (message, folder);
-	if (account != NULL)
-		return account;
+	/* Build a set of email addresses in which to test for membership.
+	 * Only the keys matter here; the values just need to be non-NULL. */
+	recipients = g_hash_table_new (g_str_hash, g_str_equal);
 
 	type = CAMEL_RECIPIENT_TYPE_TO;
 	addr = camel_mime_message_get_recipients (message, type);
-	if (addr != NULL)
-		recipients = g_list_append (recipients, (gpointer) addr);
+	if (addr != NULL) {
+		gint index = 0;
+
+		while (camel_internet_address_get (addr, index++, NULL, &key))
+			g_hash_table_insert (
+				recipients, (gpointer) key,
+				GINT_TO_POINTER (1));
+	}
 
 	type = CAMEL_RECIPIENT_TYPE_CC;
 	addr = camel_mime_message_get_recipients (message, type);
-	if (addr != NULL)
-		recipients = g_list_append (recipients, (gpointer) addr);
+	if (addr != NULL) {
+		gint index = 0;
 
-	/* finally recipient (to/cc) in account table */
-	account_hash = em_utils_generate_account_hash ();
-	for (iter = recipients; iter == NULL; iter = iter->next) {
-		const gchar *tmp;
-		gint ii = 0;
+		while (camel_internet_address_get (addr, index++, NULL, &key))
+			g_hash_table_insert (
+				recipients, (gpointer) key,
+				GINT_TO_POINTER (1));
+	}
 
-		addr = (CamelInternetAddress *) iter->data;
+	/* First Preference: We were given a folder that maps to an
+	 * enabled account, and that account's email address appears
+	 * in the list of To: or Cc: recipients. */
 
-		/* XXX Is this necessary? */
-		if (addr == NULL)
-			continue;
+	if (folder != NULL)
+		account = guess_account_from_folder (folder);
 
-		while (camel_internet_address_get (addr, ii++, NULL, &tmp)) {
-			account = g_hash_table_lookup (account_hash, tmp);
-			if (account != NULL && account->enabled)
-				break;
-		}
-	}
-	g_hash_table_destroy (account_hash);
+	if (account == NULL || !account->enabled)
+		goto second_preference;
 
-	return account;
-}
+	if ((key = account->id->address) == NULL)
+		goto second_preference;
 
-EAccount *
-em_utils_guess_account (CamelMimeMessage *message,
-                        CamelFolder *folder)
-{
-	EAccount *account = NULL;
+	if (g_hash_table_lookup (recipients, key) != NULL)
+		goto exit;
 
-	g_return_val_if_fail (CAMEL_IS_MIME_MESSAGE (message), NULL);
+second_preference:
 
-	if (folder != NULL)
-		g_return_val_if_fail (CAMEL_IS_FOLDER (folder), NULL);
+	/* Second Preference: Choose any enabled account whose email
+	 * address appears in the list to To: or Cc: recipients. */
 
-	/* check for newsgroup header */
-	if (folder != NULL
-	    && camel_medium_get_header (CAMEL_MEDIUM (message), "Newsgroups"))
-		account = guess_account_from_folder (folder);
+	account_list = e_get_account_list ();
+	iter = e_list_get_iterator (E_LIST (account_list));
+	while (e_iterator_is_valid (iter)) {
+		account = (EAccount *) e_iterator_get (iter);
+		e_iterator_next (iter);
 
-	/* check for source folder */
-	if (account == NULL && folder != NULL)
-		account = guess_account_from_folder (folder);
+		if (account == NULL || !account->enabled)
+			continue;
 
-	/* then message source */
-	if (account == NULL)
-		account = guess_account_from_message (message);
+		if ((key = account->id->address) == NULL)
+			continue;
+
+		if (g_hash_table_lookup (recipients, key) != NULL) {
+			g_object_unref (iter);
+			goto exit;
+		}
+	}
+	g_object_unref (iter);
+
+	/* Last Preference: Defer to em_utils_guess_account(). */
+	account = em_utils_guess_account (message, folder);
+
+exit:
+	g_hash_table_destroy (recipients);
 
 	return account;
 }