From: Mark Adler <madler@alumni.caltech.edu>
Subject: Fix bug in UZbunzip2() that incorrectly updated G.incnt
Origin: https://github.com/madler/unzip/commit/5e2efcd633a4a1fb95a129a75508e7d769e767be
Bug-Debian: https://bugs.debian.org/963996
X-Debian-version: 6.0-26

    Fix bug in UZbunzip2() that incorrectly updated G.incnt.
    
    The update assumed a full buffer, which is not always full. This
    could result in a false overlapped element detection when a small
    bzip2-compressed file was unzipped. This commit remedies that.

CVE: CVE-2019-13232
Upstream: https://sources.debian.org/src/unzip/6.0-29/debian/patches/25-cve-2019-13232-fix-bug-in-uzbunzip2.patch
Signed-off-by: Thomas Perale <thomas.perale@mind.be>
--- a/extract.c
+++ b/extract.c
@@ -3052,7 +3052,7 @@
 #endif
 
     G.inptr = (uch *)bstrm.next_in;
-    G.incnt = (G.inbuf + INBUFSIZ) - G.inptr;  /* reset for other routines */
+    G.incnt -= G.inptr - G.inbuf;       /* reset for other routines */
 
 uzbunzip_cleanup_exit:
     err = BZ2_bzDecompressEnd(&bstrm);