diff options
| -rw-r--r-- | src/xz/file_io.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/src/xz/file_io.c b/src/xz/file_io.c index 5eba9d87..5555891b 100644 --- a/src/xz/file_io.c +++ b/src/xz/file_io.c @@ -68,8 +68,7 @@ io_init(void) #ifdef __DJGPP__ // Avoid doing useless things when statting files. // This isn't important but doesn't hurt. - _djstat_flags = _STAT_INODE | _STAT_EXEC_EXT - | _STAT_EXEC_MAGIC | _STAT_DIRSIZE; + _djstat_flags = _STAT_EXEC_EXT | _STAT_EXEC_MAGIC | _STAT_DIRSIZE; #endif return; @@ -452,8 +451,18 @@ io_open_src_real(file_pair *pair) // Stat the source file. We need the result also when we copy // the permissions, and when unlinking. + // + // NOTE: Use stat() instead of fstat() with DJGPP, because + // then we have a better chance to get st_ino value that can + // be used in io_open_dest_real() to prevent overwriting the + // source file. +#ifdef __DJGPP__ + if (stat(pair->src_name, &pair->src_st)) + goto error_msg; +#else if (fstat(pair->src_fd, &pair->src_st)) goto error_msg; +#endif if (S_ISDIR(pair->src_st.st_mode)) { message_warning(_("%s: Is a directory, skipping"), @@ -599,6 +608,28 @@ io_open_dest_real(file_pair *pair) if (pair->dest_name == NULL) return true; +#ifdef __DJGPP__ + struct stat st; + if (stat(pair->dest_name, &st) == 0) { + // Check that it isn't a special file like "prn". + if (st.st_dev == -1) { + message_error("%s: Refusing to write to " + "a DOS special file", + pair->dest_name); + return true; + } + + // Check that we aren't overwriting the source file. + if (st.st_dev == pair->src_st.st_dev + && st.st_ino == pair->src_st.st_ino) { + message_error("%s: Output file is the same " + "as the input file", + pair->dest_name); + return true; + } + } +#endif + // If --force was used, unlink the target file first. if (opt_force && unlink(pair->dest_name) && errno != ENOENT) { message_error(_("%s: Cannot remove: %s"), |