msvcrt: Use size_t to store indexes in bsearch

[Frédéric Delanoy]

Also avoid potential integer overflow when computing median position
---
 dlls/msvcrt/misc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/dlls/msvcrt/misc.c b/dlls/msvcrt/misc.c
index c07005a..0bcbac3 100644
--- a/dlls/msvcrt/misc.c
+++ b/dlls/msvcrt/misc.c
@@ -131,15 +131,15 @@ void* CDECL MSVCRT_bsearch_s(const void *key, const void *base,
                              MSVCRT_size_t nmemb, MSVCRT_size_t size,
                              int (__cdecl *compare)(void *, const void *, const void *), void *ctx)
 {
-    ssize_t min = 0;
-    ssize_t max = nmemb - 1;
+    MSVCRT_size_t min = 0;
+    MSVCRT_size_t max = nmemb - 1;
 
     if (!MSVCRT_CHECK_PMT(size != 0)) return NULL;
     if (!MSVCRT_CHECK_PMT(compare != NULL)) return NULL;
 
     while (min <= max)
     {
-        ssize_t cursor = (min + max) / 2;
+        MSVCRT_size_t cursor = min + (max - min) / 2;
         int ret = compare(ctx, key,(const char *)base+(cursor*size));
         if (!ret)
             return (char*)base+(cursor*size);
-- 
2.0.0