negative indirect offsets are ok

diff --git a/src/softmagic.c b/src/softmagic.c
index 2bc5323119da2fd4f10351415e133a40c6e7694b..0526d997827ccfcc44fab0d16fa674a2ae4f393e 100644 (file)
--- a/src/softmagic.c
+++ b/src/softmagic.c
@@ -32,7 +32,7 @@
 #include "file.h"
 
 #ifndef        lint
-FILE_RCSID("@(#)$File: softmagic.c,v 1.254 2017/11/03 14:28:54 christos Exp $")
+FILE_RCSID("@(#)$File: softmagic.c,v 1.255 2017/11/03 23:27:49 christos Exp $")
 #endif /* lint */
 
 #include "magic.h"
@@ -1352,6 +1352,8 @@ msetoffset(struct magic_set *ms, struct magic *m, struct buffer *bb,
 {
        if (m->offset < 0) {
                if (cont_level > 0) {
+                       if (m->flag & (OFFADD|INDIROFFADD))
+                               goto normal;
                        file_error(ms, 0, "negative offset %d at continuation"
                            "level %u", m->offset, cont_level);
                        return -1;
@@ -1366,18 +1368,17 @@ msetoffset(struct magic_set *ms, struct magic *m, struct buffer *bb,
                }
                if ((size_t)-m->offset > b->elen)
                        return -1;
-               buffer_init(bb, -1, b->ebuf, bb->elen);
+               buffer_init(bb, -1, b->ebuf, b->elen);
                ms->eoffset = ms->offset = b->elen + m->offset;
        } else {
                if (cont_level == 0) {
+normal:
                        // XXX: Pass real fd, then who frees bb?
                        buffer_init(bb, -1, b->fbuf, b->flen);
                        ms->offset = m->offset;
+                       ms->eoffset = 0;
                } else {
-                       if (bb->fbuf == b->ebuf)
-                               ms->offset = ms->eoffset + m->offset;
-                       else
-                               ms->offset = m->offset;
+                       ms->offset = ms->eoffset + m->offset;
                }
        }
        if ((ms->flags & MAGIC_DEBUG) != 0) {