msvcrt: Handle negative file->_cnt value in fwrite.

b0424313 · Piotr Caban · Alexandre Julliard · 755eac8f · b0424313
Commit b0424313 authored Jun 09, 2014 by Piotr Caban Committed by Alexandre Julliard Jun 11, 2014
Hide whitespace changes
Inline Side-by-side

Showing with 5 additions and 1 deletion

file.c dlls/msvcrt/file.c +5 -1

No files found.
--- a/dlls/msvcrt/file.c
+++ b/dlls/msvcrt/file.c
@@ -3691,7 +3691,11 @@ MSVCRT_size_t CDECL MSVCRT_fwrite(const void *ptr, MSVCRT_size_t size, MSVCRT_si
    MSVCRT__lock_file(file);

    while(wrcnt) {
-        if(file->_cnt) {
+        if(file->_cnt < 0) {
+            WARN("negative file->_cnt value in %p\n", file);
+            file->_flag |= MSVCRT__IOERR;
+            break;
+        } else if(file->_cnt) {
            int pcnt=(file->_cnt>wrcnt)? wrcnt: file->_cnt;
            memcpy(file->_ptr, ptr, pcnt);
            file->_cnt -= pcnt;