Patch #788249: Pass an explicit buffer to setvbuf in PyFile_SetBufSize().
Fixes #603724. Will backport to 2.3.
diff --git a/Include/fileobject.h b/Include/fileobject.h
index e2053df..2ec4b24 100644
--- a/Include/fileobject.h
+++ b/Include/fileobject.h
@@ -19,6 +19,7 @@
char* f_buf; /* Allocated readahead buffer */
char* f_bufend; /* Points after last occupied position */
char* f_bufptr; /* Current buffer position */
+ char *f_setbuf; /* Buffer for setbuf(3) and setvbuf(3) */
#ifdef WITH_UNIVERSAL_NEWLINES
int f_univ_newline; /* Handle any newline convention */
int f_newlinetypes; /* Types of newlines seen */
diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index 13354c8..bddd81e 100644
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -283,25 +283,37 @@
void
PyFile_SetBufSize(PyObject *f, int bufsize)
{
+ PyFileObject *file = (PyFileObject *)f;
if (bufsize >= 0) {
-#ifdef HAVE_SETVBUF
int type;
switch (bufsize) {
case 0:
type = _IONBF;
break;
+#ifdef HAVE_SETVBUF
case 1:
type = _IOLBF;
bufsize = BUFSIZ;
break;
+#endif
default:
type = _IOFBF;
+#ifndef HAVE_SETVBUF
+ bufsize = BUFSIZ;
+#endif
+ break;
}
- setvbuf(((PyFileObject *)f)->f_fp, (char *)NULL,
- type, bufsize);
+ fflush(file->f_fp);
+ if (type == _IONBF) {
+ PyMem_Free(file->f_setbuf);
+ file->f_setbuf = NULL;
+ } else {
+ file->f_setbuf = PyMem_Realloc(file->f_setbuf, bufsize);
+ }
+#ifdef HAVE_SETVBUF
+ setvbuf(file->f_fp, file->f_setbuf, type, bufsize);
#else /* !HAVE_SETVBUF */
- if (bufsize <= 1)
- setbuf(((PyFileObject *)f)->f_fp, (char *)NULL);
+ setbuf(file->f_fp, file->f_setbuf);
#endif /* !HAVE_SETVBUF */
}
}
@@ -376,6 +388,7 @@
file_close(PyFileObject *f)
{
int sts = 0;
+ PyMem_Free(f->f_setbuf);
if (f->f_fp != NULL) {
if (f->f_close != NULL) {
Py_BEGIN_ALLOW_THREADS
@@ -1928,6 +1941,7 @@
}
if (open_the_file(foself, name, mode) == NULL)
goto Error;
+ foself->f_setbuf = NULL;
PyFile_SetBufSize(self, bufsize);
goto Done;