# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 1313001601 18000
# Node ID 2ef2d3a5cd2d78bc1634b695be98bf2b5a10d3d4
# Parent  eb87fbc6d7020f02cb80c1c0de72ab4977283c8c
parsers: avoid pointer aliasing

Newer versions of GCC have aggressive pointer alias optimizations that
might get fooled by our pointer manipulations. These issues shouldn't
be encountered in practice because distutils compiles extensions with
-fno-strict-alias but the code was not valid according to the standard.

diff -r eb87fbc6d702 -r 2ef2d3a5cd2d mercurial/mpatch.c
--- a/mercurial/mpatch.c	Wed Aug 10 13:25:35 2011 -0500
+++ b/mercurial/mpatch.c	Wed Aug 10 13:40:01 2011 -0500
@@ -238,7 +238,7 @@
 	struct flist *l;
 	struct frag *lt;
 	const char *data = bin + 12, *end = bin + len;
-	char decode[12]; /* for dealing with alignment issues */
+	uint32_t decode[3]; /* for dealing with alignment issues */
 
 	/* assume worst case size, we won't have many of these lists */
 	l = lalloc(len / 12);
@@ -249,9 +249,9 @@
 
 	while (data <= end) {
 		memcpy(decode, bin, 12);
-		lt->start = ntohl(*(uint32_t *)decode);
-		lt->end = ntohl(*(uint32_t *)(decode + 4));
-		lt->len = ntohl(*(uint32_t *)(decode + 8));
+		lt->start = ntohl(decode[0]);
+		lt->end = ntohl(decode[1]);
+		lt->len = ntohl(decode[2]);
 		if (lt->start > lt->end)
 			break; /* sanity check */
 		bin = data + lt->len;
@@ -397,7 +397,7 @@
 	long orig, start, end, len, outlen = 0, last = 0;
 	int patchlen;
 	char *bin, *binend, *data;
-	char decode[12]; /* for dealing with alignment issues */
+	uint32_t decode[3]; /* for dealing with alignment issues */
 
 	if (!PyArg_ParseTuple(args, "ls#", &orig, &bin, &patchlen))
 		return NULL;
@@ -407,9 +407,9 @@
 
 	while (data <= binend) {
 		memcpy(decode, bin, 12);
-		start = ntohl(*(uint32_t *)decode);
-		end = ntohl(*(uint32_t *)(decode + 4));
-		len = ntohl(*(uint32_t *)(decode + 8));
+		start = ntohl(decode[0]);
+		end = ntohl(decode[1]);
+		len = ntohl(decode[2]);
 		if (start > end)
 			break; /* sanity check */
 		bin = data + len;
diff -r eb87fbc6d702 -r 2ef2d3a5cd2d mercurial/parsers.c
--- a/mercurial/parsers.c	Wed Aug 10 13:25:35 2011 -0500
+++ b/mercurial/parsers.c	Wed Aug 10 13:40:01 2011 -0500
@@ -170,7 +170,7 @@
 	int state, mode, size, mtime;
 	unsigned int flen;
 	int len;
-	char decode[16]; /* for alignment */
+	uint32_t decode[4]; /* for alignment */
 
 	if (!PyArg_ParseTuple(args, "O!O!s#:parse_dirstate",
 			      &PyDict_Type, &dmap,
@@ -194,10 +194,10 @@
 		/* unpack header */
 		state = *cur;
 		memcpy(decode, cur + 1, 16);
-		mode = ntohl(*(uint32_t *)(decode));
-		size = ntohl(*(uint32_t *)(decode + 4));
-		mtime = ntohl(*(uint32_t *)(decode + 8));
-		flen = ntohl(*(uint32_t *)(decode + 12));
+		mode = ntohl(decode[0]);
+		size = ntohl(decode[1]);
+		mtime = ntohl(decode[2]);
+		flen = ntohl(decode[3]);
 		cur += 17;
 		if (cur + flen > end || cur + flen < cur) {
 			PyErr_SetString(PyExc_ValueError, "overflow in dirstate");
@@ -264,27 +264,27 @@
 	int comp_len, uncomp_len, base_rev, link_rev, parent_1, parent_2;
 	const char *c_node_id;
 	const char *end = data + size;
-	char decode[64]; /* to enforce alignment with inline data */
+	uint32_t decode[8]; /* to enforce alignment with inline data */
 
 	while (data < end) {
 		unsigned int step;
 
-		memcpy(decode, data, 64);
-		offset_flags = ntohl(*((uint32_t *) (decode + 4)));
+		memcpy(decode, data, 32);
+		offset_flags = ntohl(decode[1]);
 		if (n == 0) /* mask out version number for the first entry */
 			offset_flags &= 0xFFFF;
 		else {
-			uint32_t offset_high =  ntohl(*((uint32_t *)decode));
+			uint32_t offset_high =  ntohl(decode[0]);
 			offset_flags |= ((uint64_t)offset_high) << 32;
 		}
 
-		comp_len = ntohl(*((uint32_t *)(decode + 8)));
-		uncomp_len = ntohl(*((uint32_t *)(decode + 12)));
-		base_rev = ntohl(*((uint32_t *)(decode + 16)));
-		link_rev = ntohl(*((uint32_t *)(decode + 20)));
-		parent_1 = ntohl(*((uint32_t *)(decode + 24)));
-		parent_2 = ntohl(*((uint32_t *)(decode + 28)));
-		c_node_id = decode + 32;
+		comp_len = ntohl(decode[2]);
+		uncomp_len = ntohl(decode[3]);
+		base_rev = ntohl(decode[4]);
+		link_rev = ntohl(decode[5]);
+		parent_1 = ntohl(decode[6]);
+		parent_2 = ntohl(decode[7]);
+		c_node_id = data + 32;
 
 		entry = Py_BuildValue("Liiiiiis#", offset_flags, comp_len,
 			      uncomp_len, base_rev, link_rev,