Add indexing for the mimetype term

This adds the indexing support for the "mimetype:" term and removes
the broken test flag.  The indexing is probablistic in Xapian terms,
which gives a better experience to end users.  Standard content-types
of the form "foo/bar" are automatically interpreted as phrases in
Xapian due to the embedded slash.

Assume, separate messages with application/pdf and application/x-pdf
are indexed, then:

- mimetype:application/x-pdf will find only the application/x-pdf
- mimetype:application/pdf will find only the application/pdf
- mimetype:pdf will find both of the messages

2 files changed, 11 insertions, 0 deletions

diff --git a/lib/database.cc b/lib/database.cc
index 0d2c4172..3974e2ed 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -254,6 +254,7 @@ static prefix_t PROBABILISTIC_PREFIX[]= {
     { "from",			"XFROM" },
     { "to",			"XTO" },
     { "attachment",		"XATTACHMENT" },
+    { "mimetype",		"XMIMETYPE"},
     { "subject",		"XSUBJECT"},
 };
 
diff --git a/lib/index.cc b/lib/index.cc
index 1a2e63df..c88ed8d7 100644
--- a/lib/index.cc
+++ b/lib/index.cc
@@ -318,6 +318,16 @@ _index_mime_part (notmuch_message_t *message,
 	return;
     }
 
+    GMimeContentType *content_type = g_mime_object_get_content_type(part);
+    if (content_type) {
+	char *mime_string = g_mime_content_type_to_string(content_type);
+	if (mime_string)
+	{
+	    _notmuch_message_gen_terms (message, "mimetype", mime_string);
+	    g_free(mime_string);
+	}
+    }
+
     if (GMIME_IS_MULTIPART (part)) {
 	GMimeMultipart *multipart = GMIME_MULTIPART (part);
 	int i;