parsers: make pack_dirstate take now in integer for consistency On recent OS, 'stat.st_mtime' has a double precision floating point value to represent nano seconds, but it is not wide enough for actual file timestamp: nowadays, only 52 - 32 = 20 bit width is available for decimal places in sec. Therefore, casting it to 'int' may cause unexpected result. See also changeset 13272104bb07 fixing issue4836 for detail. For example, changed file A may be treated as "clean" unexpectedly in steps below. "rounded now" is the value gotten by rounding via 'int(st.st_mtime)' or so. ---------------------+--------------------+------------------------ "now" | | timestamp of A (time_t) float rounded time_t| action | FS dirstate ------ ------- ------+--------------------+-------- --------------- N+.nnn N N | | --- --- | update file A | N | dirstate.normal(A) | N N+.999 N+1 N | | | dirstate.write() | N (*1) | : | | change file A | N | : | N+1.00 N+1 N+1 | | | "hg status" (*2) | N N ------ ------- ------+--------------------+-------- --------------- Timestamp N of A in dirstate isn't dropped at (*1), because "rounded now" is N+1 at that time, even if 'st_mtime' in 'time_t' is still N. Then, file A is unexpectedly treated as "clean" at (*2) in this case. For consistent handling of 'stat.st_mtime', this patch makes 'pack_dirstate()' take 'now' argument not in floating point but in integer. This patch makes 'PyArg_ParseTuple()' in 'pack_dirstate()' use format 'i' (= checking type mismatch or overflow), even though it is ensured that 'now' is in the range of 32bit signed integer by masking with '_rangemask' (= 0x7fffffff) on caller side. It should be cheaper enough than packing itself, and useful to detect that legacy code invokes 'pack_dirstate()' with 'now' in floating point value.

--- a/mercurial/parsers.c	Tue Sep 29 00:18:49 2015 -0700
+++ b/mercurial/parsers.c	Wed Oct 14 02:40:04 2015 +0900
@@ -551,9 +551,9 @@
 	Py_ssize_t nbytes, pos, l;
 	PyObject *k, *v = NULL, *pn;
 	char *p, *s;
-	double now;
+	int now;
 
-	if (!PyArg_ParseTuple(args, "O!O!Od:pack_dirstate",
+	if (!PyArg_ParseTuple(args, "O!O!Oi:pack_dirstate",
 			      &PyDict_Type, &map, &PyDict_Type, &copymap,
 			      &pl, &now))
 		return NULL;
@@ -622,7 +622,7 @@
 		mode = tuple->mode;
 		size = tuple->size;
 		mtime = tuple->mtime;
-		if (state == 'n' && mtime == (uint32_t)now) {
+		if (state == 'n' && mtime == now) {
 			/* See pure/parsers.py:pack_dirstate for why we do
 			 * this. */
 			mtime = -1;