Xen4.1 initializes some unspecified sexpr config items to an empty string, unlike previous Xen versions that would leave the item unset. E.g. the kernel item for an HVM guest (non-direct kernel boot): Xen4.0 and earlier ... (image (hvm (kernel ) ... Xen4.1 ... (image (hvm (kernel '') ... The empty string for kernel causes some grief in subsequent parsing where existence of specified kernel is checked, e.g. if (!def->os.kernel) ... This patch solves the problem in sexpr_node_copy() by not copying a node containing an empty string. --- src/util/sexpr.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/util/sexpr.c b/src/util/sexpr.c index 0e30087..3523d76 100644 --- a/src/util/sexpr.c +++ b/src/util/sexpr.c @@ -519,7 +519,7 @@ int sexpr_node_copy(const struct sexpr *sexpr, const char *node, char **dst) { const char *val = sexpr_node(sexpr, node); - if (val) { + if (val && *val) { *dst = strdup(val); if (!(*dst)) return -1; -- 1.7.7