Merge branch '4598_tar_segfault'

* 4598_tar_segfault:
  tar: initialize variables passed to stoint().
  (decode_num): simplify expression.
  Ticket #4598: fix segfault on open TAR archive.

Signed-off-by: Yury V. Zaytsev <yury@shurup.com>

Author: aborodin

src/vfs/tar/tar-sparse.c

@@ -253,11 +253,11 @@ static struct tar_sparse_optab const pax_optab = {
 static gboolean
 decode_num (uintmax_t *num, const char *arg, uintmax_t maxval)
 {
-    char *arg_lim;
-    gboolean overflow;
+    char *arg_lim = NULL;
+    gboolean overflow = FALSE;
 
     *num = stoint (arg, &arg_lim, &overflow, 0, maxval);
-    return (((arg_lim == arg ? 1 : 0) | (*arg_lim != '\0') | (overflow ? 1 : 0)) == 0);
+    return !(arg_lim == arg || *arg_lim != '\0' || overflow);
 }
 
 /* --------------------------------------------------------------------------------------------- */

src/vfs/tar/tar-xheader.c

@@ -255,12 +255,13 @@ static struct timespec
 decode_timespec (const char *arg, char **arg_lim, gboolean parse_fraction)
 {
     int ns = -1;
-    gboolean overflow;
+    gboolean overflow = FALSE;
     time_t s;
-    char const *p = *arg_lim;
+    char const *p;
     struct timespec r;
 
     s = stoint (arg, arg_lim, &overflow, TYPE_MINIMUM (time_t), TYPE_MAXIMUM (time_t));
+    p = *arg_lim;
 
     if (p != arg)
     {
@@ -340,8 +341,8 @@ static gboolean
 decode_signed_num (intmax_t *num, const char *arg, intmax_t minval, uintmax_t maxval,
                    const char *keyword)
 {
-    char *arg_lim;
-    gboolean overflow;
+    char *arg_lim = NULL;
+    gboolean overflow = FALSE;
     intmax_t u;
 
     (void) keyword;
@@ -582,7 +583,7 @@ decode_record (struct xheader *xhdr, char **ptr,
     char *start = *ptr;
     char *p = start;
     idx_t len;
-    char *len_lim;
+    char *len_lim = NULL;
     const char *keyword;
     char *nextp;
     idx_t len_max;
@@ -801,8 +802,8 @@ sparse_map_decoder (struct tar_stat_info *st, const char *keyword, const char *a
     while (TRUE)
     {
         off_t u;
-        char *delim;
-        gboolean overflow;
+        char *delim = NULL;
+        gboolean overflow = FALSE;
 
         u = stoint (arg, &delim, &overflow, 0, TYPE_MAXIMUM (off_t));