Don't compress or decompress special files unless writing

to stdout even if --force is used.

--force will still enable compression of symlinks, but only
in case they point to a regular file.

The new way simply seems more reasonable. It matches gzip's
behavior while the old one matched bzip2's behavior.

diff --git a/src/xz/file_io.c b/src/xz/file_io.c
index 18b7b04..d94e232 100644 (file)
--- a/src/xz/file_io.c
+++ b/src/xz/file_io.c
@@ -275,9 +275,14 @@ io_open_src(file_pair *pair)
                return false;
        }
 
+       // Symlinks are not followed unless writing to stdout or --force
+       // was used.
+       const bool follow_symlinks = opt_stdout || opt_force;
+
        // We accept only regular files if we are writing the output
-       // to disk too, and if --force was not given.
-       const bool reg_files_only = !opt_stdout && !opt_force;
+       // to disk too. bzip2 allows overriding this with --force but
+       // gzip and xz don't.
+       const bool reg_files_only = !opt_stdout;
 
        // Flags for open()
        int flags = O_RDONLY | O_BINARY | O_NOCTTY;
@@ -293,13 +298,13 @@ io_open_src(file_pair *pair)
 #endif
 
 #if defined(O_NOFOLLOW)
-       if (reg_files_only)
+       if (!follow_symlinks)
                flags |= O_NOFOLLOW;
 #elif !defined(TUKLIB_DOSLIKE)
        // Some POSIX-like systems lack O_NOFOLLOW (it's not required
        // by POSIX). Check for symlinks with a separate lstat() on
        // these systems.
-       if (reg_files_only) {
+       if (!follow_symlinks) {
                struct stat st;
                if (lstat(pair->src_name, &st)) {
                        message_error("%s: %s", pair->src_name,
@@ -374,7 +379,7 @@ io_open_src(file_pair *pair)
                        was_symlink = true;
 
 #      else
-               if (errno == ELOOP && reg_files_only) {
+               if (errno == ELOOP && !follow_symlinks) {
                        const int saved_errno = errno;
                        struct stat st;
                        if (lstat(pair->src_name, &st) == 0