Subject: Handle parsing guids in big endian machines (Christoph Biedl)
Origin: upstream, commit FILE5_47-93-g7a2b2a4b <https://github.com/file/file/commit/FILE5_47-93-g7a2b2a4b>
Author: Christos Zoulas <christos@zoulas.com>
Date: Sun May 17 17:10:25 2026 +0000

--- a/src/compress.c
+++ b/src/compress.c
@@ -125,12 +125,11 @@
 static int
 zlibcmp(const unsigned char *buf)
 {
-	unsigned short x = 1;
-	unsigned char *s = CAST(unsigned char *, CAST(void *, &x));
+	unsigned short x;
 
 	if ((buf[0] & 0xf) != 8 || (buf[0] & 0x80) != 0)
 		return 0;
-	if (s[0] != 1)	/* endianness test */
+	if (file_bigendian())	/* endianness test */
 		x = buf[0] | (buf[1] << 8);
 	else
 		x = buf[1] | (buf[0] << 8);
--- a/src/file.h
+++ b/src/file.h
@@ -596,6 +596,7 @@
 file_protected uintmax_t file_varint2uintmax_t(const unsigned char *, int,
     size_t *);
 
+file_protected int file_bigendian(void);
 file_protected void file_badread(struct magic_set *);
 file_protected void file_badseek(struct magic_set *);
 file_protected void file_oomem(struct magic_set *, size_t);
--- a/src/funcs.c
+++ b/src/funcs.c
@@ -52,6 +52,18 @@
 #define SIZE_MAX	((size_t)~0)
 #endif
 
+file_protected int
+file_bigendian(void)
+{
+	union {
+		unsigned short x;
+		unsigned char s[sizeof(unsigned short)];
+	} u;
+
+	u.x = 1;
+	return u.s[0] != 1;
+}
+
 file_protected char *
 file_copystr(char *buf, size_t blen, size_t width, const char *str)
 {
@@ -932,6 +944,13 @@
 	    !getxvalue(&g->data4[6], s + 8, 2) ||
 	    !getxvalue(&g->data4[7], s + 10, 2))
 		return -1;
+
+	if (file_bigendian()) {
+		g->data1 = file_swap4(g->data1);
+		g->data2 = file_swap2(g->data2);
+		g->data3 = file_swap2(g->data3);
+
+	}
 	return 0;
 }