* win32/win32.c (rb_w32_read): limit read size to 16KB if the file

  seems to be console.  [ruby-core:28902]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27029 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 17 insertions, 2 deletions

diff --git a/win32/win32.c b/win32/win32.c
index 8216ac9918..58c24d4deb 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -4835,6 +4835,8 @@ rb_w32_read(int fd, void *buf, size_t size)
     DWORD read;
     DWORD wait;
     DWORD err;
+    size_t len;
+    size_t ret;
     OVERLAPPED ol, *pol = NULL;
 
     if (is_socket(sock))
@@ -4856,6 +4858,12 @@ rb_w32_read(int fd, void *buf, size_t size)
 	return 0;
     }
 
+    ret = 0;
+  retry:
+    /* get rid of console writing bug */
+    len = (_osfile(fd) & FDEV) ? min(16 * 1024, size) : size;
+    size -= len;
+
     /* if have cancel_io, use Overlapped I/O */
     if (cancel_io) {
 	memset(&ol, 0, sizeof(ol));
@@ -4884,7 +4892,7 @@ rb_w32_read(int fd, void *buf, size_t size)
 	pol = &ol;
     }
 
-    if (!ReadFile((HANDLE)_osfhnd(fd), buf, size, &read, pol)) {
+    if (!ReadFile((HANDLE)_osfhnd(fd), buf, len, &read, pol)) {
 	err = GetLastError();
 	if (err != ERROR_IO_PENDING) {
 	    if (err == ERROR_ACCESS_DENIED)
@@ -4940,9 +4948,16 @@ rb_w32_read(int fd, void *buf, size_t size)
 	}
     }
 
+    ret += read;
+    if (read == len) {
+	buf = (char *)buf + len;
+	if (size > 0)
+	    goto retry;
+    }
+
     MTHREAD_ONLY(LeaveCriticalSection(&_pioinfo(fd)->lock));
 
-    return read;
+    return ret;
 }
 
 #undef write