imap: Code cleanup - use istream-sized for GETMETADATA reply

This avoids doing the same work explicitly.

src/imap/cmd-getmetadata.c

@@ -3,6 +3,7 @@
 #include "imap-common.h"
 #include "str.h"
 #include "istream.h"
+#include "istream-sized.h"
 #include "ostream.h"
 #include "mailbox-list-iter.h"
 #include "imap-utf7.h"
@@ -22,7 +23,6 @@ struct imap_getmetadata_context {
 	unsigned int depth;
 
 	struct istream *cur_stream;
-	uoff_t cur_stream_size;
 
 	struct imap_metadata_iter *iter;
 	string_t *iter_entry_prefix;
@@ -203,39 +203,31 @@ static void cmd_getmetadata_send_entry(struct imap_getmetadata_context *ctx,
 		str_printfa(str, " ~{%"PRIuUOFF_T"}\r\n", value_len);
 		o_stream_nsend(client->output, str_data(str), str_len(str));
 
-		i_assert(value.value_stream->v_offset == 0);
-		ctx->cur_stream_size = value_len;
-		ctx->cur_stream = value.value_stream;
+		ctx->cur_stream = i_stream_create_sized(value.value_stream, value_len);
+		i_stream_unref(&value.value_stream);
 	}
 }
 
 static bool
 cmd_getmetadata_stream_continue(struct imap_getmetadata_context *ctx)
 {
+	int ret;
+
 	o_stream_set_max_buffer_size(ctx->cmd->client->output, 0);
-	(void)o_stream_send_istream(ctx->cmd->client->output, ctx->cur_stream);
+	ret = o_stream_send_istream(ctx->cmd->client->output, ctx->cur_stream);
 	o_stream_set_max_buffer_size(ctx->cmd->client->output, (size_t)-1);
 
-	if (ctx->cur_stream->stream_errno != 0) {
+	if (ret > 0) {
+		/* finished */
+		return TRUE;
+	} else if (ret < 0) {
 		i_error("read(%s) failed: %s",
 			i_stream_get_name(ctx->cur_stream),
 			i_stream_get_error(ctx->cur_stream));
 		client_disconnect(ctx->cmd->client,
 				  "Internal GETMETADATA failure");
 		return TRUE;
 	}
-	if (ctx->cur_stream->v_offset == ctx->cur_stream_size) {
-		/* finished */
-		return TRUE;
-	}
-	if (!i_stream_have_bytes_left(ctx->cur_stream)) {
-		/* Input stream gave less data than expected */
-		i_error("read(%s): GETMETADATA stream had less data than expected",
-			i_stream_get_name(ctx->cur_stream));
-		client_disconnect(ctx->cmd->client,
-				  "Internal GETMETADATA failure");
-		return TRUE;
-	}
 	o_stream_set_flush_pending(ctx->cmd->client->output, TRUE);
 	return FALSE;
 }