SIGSEGV with leafreaf in typedef

[lukasmacko]

Libyang crashes with segmentation fault, when it parse leafref in ietf-interfaces

node = parent_node->module->data;

#0  0x00007ffff7b754bc in resolve_path_arg_schema (
    path=0x61b740 "/ietf-interfaces:interfaces/ietf-interfaces:interface/ietf-interfaces:name", 
    parent_node=0x0, first=1, line=54, ret=0x61b620)
    at /home/lukas/playground/libyang/src/resolve.c:2407
#1  0x00007ffff7b77e57 in resolve_unres_schema_item (mod=0x61b520, item=0x61b5f8, 
    type=UNRES_TYPE_LEAFREF, str_snode=0x0, unres=0x6090f0, first=1, line=54)
    at /home/lukas/playground/libyang/src/resolve.c:3575
#2  0x00007ffff7b7874d in unres_schema_add_node (mod=0x61b520, unres=0x6090f0, item=0x61b5f8, 
    type=UNRES_TYPE_LEAFREF, snode=0x0, line=54) at /home/lukas/playground/libyang/src/resolve.c:3813
#3  0x00007ffff7b84066 in fill_yin_type (module=0x61b520, parent=0x0, yin=0x6134f0, type=0x61b5f8, 
    unres=0x6090f0) at /home/lukas/playground/libyang/src/parser_yin.c:975
#4  0x00007ffff7b77ead in resolve_unres_schema_item (mod=0x61b520, item=0x61b5f8, 
    type=UNRES_TYPE_DER, str_snode=0x0, unres=0x6090f0, first=1, line=54)
    at /home/lukas/playground/libyang/src/resolve.c:3588
#5  0x00007ffff7b7874d in unres_schema_add_node (mod=0x61b520, unres=0x6090f0, item=0x61b5f8, 
    type=UNRES_TYPE_DER, snode=0x0, line=54) at /home/lukas/playground/libyang/src/resolve.c:3813
#6  0x00007ffff7b84c6d in fill_yin_typedef (module=0x61b520, parent=0x0, yin=0x613960, 
    tpdf=0x61b5d0, unres=0x6090f0) at /home/lukas/playground/libyang/src/parser_yin.c:1185
#7  0x00007ffff7b94796 in read_sub_module (module=0x61b520, yin=0x60e090, unres=0x6090f0)
    at /home/lukas/playground/libyang/src/parser_yin.c:5302
#8  0x00007ffff7b954cf in yin_read_module (ctx=0x603010, 
    data=0x7ffff7ff3000 "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<module name=\"ietf-interfaces\"\n        xmlns=\"urn:ietf:params:xml:ns:yang:yin:1\"\n        xmlns:if=\"urn:ietf:params:xml:ns:yang:ietf-interfaces\"\n        xmlns:yan"..., implement=1, unres=0x6090f0)
    at /home/lukas/playground/libyang/src/parser_yin.c:5508
#9  0x00007ffff7b9b691 in lys_parse_data (ctx=0x603010, 
    data=0x7ffff7ff3000 "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<module name=\"ietf-interfaces\"\n        xmlns=\"urn:ietf:params:xml:ns:yang:yin:1\"\n        xmlns:if=\"urn:ietf:params:xml:ns:yang:ietf-interfaces\"\n        xmlns:yan"..., format=LYS_IN_YIN)
    at /home/lukas/playground/libyang/src/tree_schema.c:1091
#10 0x00007ffff7b9ba85 in lys_parse_fd (ctx=0x603010, fd=3, format=LYS_IN_YIN)