erts: Use correct type for ReadFile bytes read

Using a 64bit type for bytes read will not always clear the higher bits.

2 files changed, 5 insertions, 2 deletions

diff --git a/erts/emulator/drivers/common/efile_drv.c b/erts/emulator/drivers/common/efile_drv.c
index 22328fcd11..69acfc9dfd 100644
--- a/erts/emulator/drivers/common/efile_drv.c
+++ b/erts/emulator/drivers/common/efile_drv.c
@@ -1149,7 +1149,7 @@ static void invoke_read_line(void *data)
 {
     struct t_data *d = (struct t_data *) data;
     int status;
-    size_t read_size;
+    size_t read_size = 0;
     int local_loop = (d->again == 0);
     DTRACE_INVOKE_SETUP(FILE_READ_LINE);
 
diff --git a/erts/emulator/drivers/win32/win_efile.c b/erts/emulator/drivers/win32/win_efile.c
index f2b0c8a843..1059fa5c3a 100644
--- a/erts/emulator/drivers/win32/win_efile.c
+++ b/erts/emulator/drivers/win32/win_efile.c
@@ -1159,8 +1159,11 @@ char* buf;			/* Buffer to read into. */
 size_t count;			/* Number of bytes to read. */
 size_t* pBytesRead;		/* Where to return number of bytes read. */
 {
-    if (!ReadFile((HANDLE) fd, buf, count, (DWORD *) pBytesRead, NULL))
+    DWORD nbytes = 0;
+    if (!ReadFile((HANDLE) fd, buf, count, &nbytes, NULL))
 	return set_error(errInfo);
+
+    *pBytesRead = nbytes;
     return 1;
 }