# HG changeset patch
# User Adrian Buehlmann <adrian@cadifra.com>
# Date 1337114207 -7200
# Node ID 5b1f869b5548e06a79648be96c40760d5e21e1a4
# Parent  eab8ca175262db028a8327754796b235724d5de5
bdiff: check and cast first parameter value on putbe32() calls

Eliminates

  mercurial/bdiff.c(383) : warning C4244: 'function' : conversion from '__int64'
  to 'uint32_t', possible loss of data
  mercurial/bdiff.c(384) : warning C4244: 'function' : conversion from '__int64'
  to 'uint32_t', possible loss of data
  mercurial/bdiff.c(385) : warning C4244: 'function' : conversion from
  'Py_ssize_t' to 'uint32_t', possible loss of data

when compiling for Windows x64 target using the Microsoft compiler.

diff -r eab8ca175262 -r 5b1f869b5548 mercurial/bdiff.c
--- a/mercurial/bdiff.c	Tue May 15 22:36:27 2012 +0200
+++ b/mercurial/bdiff.c	Tue May 15 22:36:47 2012 +0200
@@ -381,9 +381,18 @@
 	for (h = l.next; h; h = h->next) {
 		if (h->a1 != la || h->b1 != lb) {
 			len = bl[h->b1].l - bl[lb].l;
-			putbe32(al[la].l - al->l, rb);
-			putbe32(al[h->a1].l - al->l, rb + 4);
-			putbe32(len, rb + 8);
+
+#define checkputbe32(__x, __c) \
+	if (__x > UINT_MAX) { \
+		PyErr_SetString(PyExc_ValueError, \
+		                "bdiff: value too large for putbe32"); \
+		goto nomem; \
+	} \
+	putbe32((uint32_t)(__x), __c);
+
+			checkputbe32(al[la].l - al->l, rb);
+			checkputbe32(al[h->a1].l - al->l, rb + 4);
+			checkputbe32(len, rb + 8);
 			memcpy(rb + 12, bl[lb].l, len);
 			rb += 12 + len;
 		}