be PDP-endian host compatible when writing binary cpio headers

diff --git a/libarchive/archive_write_set_format_cpio_binary.c b/libarchive/archive_write_set_format_cpio_binary.c
index 01aca6f08e0705ac97dec1defc5ea9eb12814837..b0081888897616565068c9fef5c3f14d069eb9d4 100644 (file)
--- a/libarchive/archive_write_set_format_cpio_binary.c
+++ b/libarchive/archive_write_set_format_cpio_binary.c
@@ -121,8 +121,7 @@ PACKED(struct cpio_binary_header {
  * #define PUTI16(v,sv) {U.s[0]=1;if(U.c[0]) v=sv; else U.s[0]=sv,U.c[2]=U.c[1],U.c[3]=U.c[0],v=U.s[1];}
  * #define PUTI32(v,lv) {char_t Ut;U.l=1;if(U.c[0]) U.l=lv,v[0]=U.s[1],v[1]=U.s[0]; else U.l=lv,Ut=U.c[0],U.c[0]=U.c[1],U.c[1]=Ut,Ut=U.c[2],U.c[2]=U.c[3],U.c[3]=Ut,v[0]=U.s[0],v[1]=U.s[1];}
  *
- * ...but it feels a little better to do it like this (which by the way,
- * assumes that it will never be run on a PDP-11):
+ * ...but it feels a little better to do it like this:
  */
 
 static uint16_t swap16(uint16_t in) {
@@ -149,21 +148,18 @@ static uint32_t swap32(uint32_t in) {
                uint8_t c[4];
        } U;
        U.l = 1;
-       if (U.c[0]) {
+       if (U.c[0]) {           /* Little-endian */
                uint16_t t;
                U.l = in;
                t = U.s[0];
                U.s[0] = U.s[1];
                U.s[1] = t;
-       } else {
-               uint8_t t;
+       } else if (U.c[3]) {    /* Big-endian */
+               U.l = in;
+               U.s[0] = swap16(U.s[0]);
+               U.s[1] = swap16(U.s[1]);
+       } else {                /* PDP-endian */
                U.l = in;
-               t = U.c[0];
-               U.c[0] = U.c[1];
-               U.c[1] = t;
-               t = U.c[2];
-               U.c[2] = U.c[3];
-               U.c[3] = t;
        }
        return U.l;
 }