svn commit: r290231 - head/lib/libc/stdio

[Andrey A. Chernov]

Author: ache
Date: Sun Nov  1 06:47:05 2015
New Revision: 290231
URL: https://svnweb.freebsd.org/changeset/base/290231

Log:
  Addition to prev. commit.
  In some edge cases fp->_p can be changed in _sseek(), recalculate.
  
  PR:     204156
  MFC after:      1 week

Modified:
  head/lib/libc/stdio/ftell.c

Modified: head/lib/libc/stdio/ftell.c
==============================================================================
--- head/lib/libc/stdio/ftell.c	Sun Nov  1 06:15:14 2015	(r290230)
+++ head/lib/libc/stdio/ftell.c	Sun Nov  1 06:47:05 2015	(r290231)
@@ -125,10 +125,6 @@ _ftello(FILE *fp, fpos_t *offset)
 		 * underlying object.
 		 */
 		n = fp->_p - fp->_bf._base;
-		if (pos > OFF_MAX - n) {
-			errno = EOVERFLOW;
-			return (1);
-		}
 		if (n > 0 &&
 		    ((fp->_flags & __SAPP) || (fp->_flags2 & __S2OAP))) {
 			int serrno = errno;
@@ -147,6 +143,12 @@ _ftello(FILE *fp, fpos_t *offset)
 				}
 			}
 			errno = serrno;
+			/* fp->_p can be changed in _sseek(), recalculate. */
+			n = fp->_p - fp->_bf._base;
+		}
+		if (pos > OFF_MAX - n) {
+			errno = EOVERFLOW;
+			return (1);
 		}
 		pos += n;
 	}