[PATCH 19/23] lib: refactor _notmuch_messsage_file_get_combined_header

[David Bremner <david@tethera.net>]

We need to rewrite the loop for gmime-3.0; move the loop body to its
own function to avoid code duplication.  Keep the common exit via
"goto DONE" to make this pure code movement.  It's important to note
that the existing exit path only deallocates the iterator.
---
 lib/message-file.c | 57 ++++++++++++++++++++++++++++++------------------------
 1 file changed, 32 insertions(+), 25 deletions(-)

diff --git a/lib/message-file.c b/lib/message-file.c
index db18b163..7d38ebd0 100644
--- a/lib/message-file.c
+++ b/lib/message-file.c
@@ -201,6 +201,37 @@ _notmuch_message_file_get_mime_message (notmuch_message_file_t *message,
  *
  * Return NULL on errors, empty string for non-existing headers.
  */
+
+static char *
+_extend_header (char *combined, const char *value) {
+    char *decoded;
+
+    decoded = g_mime_utils_header_decode_text (value);
+    if (! decoded) {
+	if (combined) {
+	    g_free (combined);
+	    combined = NULL;
+	}
+	goto DONE;
+    }
+
+    if (combined) {
+	char *tmp = g_strdup_printf ("%s %s", combined, decoded);
+	g_free (decoded);
+	g_free (combined);
+	if (! tmp) {
+	    combined = NULL;
+	    goto DONE;
+	}
+
+	combined = tmp;
+    } else {
+	combined = decoded;
+    }
+ DONE:
+    return combined;
+}
+
 static char *
 _notmuch_message_file_get_combined_header (notmuch_message_file_t *message,
 					   const char *header)
@@ -222,37 +253,13 @@ _notmuch_message_file_get_combined_header (notmuch_message_file_t *message,
 
     do {
 	const char *value;
-	char *decoded;
-
 	if (strcasecmp (g_mime_header_iter_get_name (iter), header) != 0)
 	    continue;
 
 	/* Note that GMime retains ownership of value... */
 	value = g_mime_header_iter_get_value (iter);
 
-	/* ... while decoded needs to be freed with g_free(). */
-	decoded = g_mime_utils_header_decode_text (value);
-	if (! decoded) {
-	    if (combined) {
-		g_free (combined);
-		combined = NULL;
-	    }
-	    goto DONE;
-	}
-
-	if (combined) {
-	    char *tmp = g_strdup_printf ("%s %s", combined, decoded);
-	    g_free (decoded);
-	    g_free (combined);
-	    if (! tmp) {
-		combined = NULL;
-		goto DONE;
-	    }
-
-	    combined = tmp;
-	} else {
-	    combined = decoded;
-	}
+	combined = _extend_header (combined, value);
     } while (g_mime_header_iter_next (iter));
 
     /* Return empty string for non-existing headers. */
-- 
2.11.0