Disallow open()ing of directories. Closes SF bug 487277.

diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index c8fb214e2fcbd46ad9671ce23f7044e1c021f18a..924ddcf0b56bfc5f18326571fd1a292f0939289c 100644 (file)
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -56,6 +56,32 @@ PyFile_Name(PyObject *f)
                return ((PyFileObject *)f)->f_name;
 }
 
+/* On Unix, fopen will succeed for directories.
+   In Python, there should be no file objects referring to
+   directories, so we need a check.  */
+
+static PyFileObject*
+dircheck(PyFileObject* f)
+{
+#if defined(HAVE_FSTAT) && defined(S_IFDIR) && defined(EISDIR)
+       struct stat buf;
+       if (f->f_fp == NULL)
+               return f;
+       if (fstat(fileno(f->f_fp), &buf) == 0 &&
+           S_ISDIR(buf.st_mode)) {
+#ifdef HAVE_STRERROR
+               char *msg = strerror(EISDIR);
+#else
+               char *msg = "Is a directory";
+#endif
+               PyObject *exc = PyObject_CallFunction(PyExc_IOError, "(is)", EISDIR, msg);
+               PyErr_SetObject(PyExc_IOError, exc);
+               return NULL;
+       }
+#endif
+       return f;
+}
+
 
 static PyObject *
 fill_file_fields(PyFileObject *f, FILE *fp, char *name, char *mode,
@@ -77,6 +103,7 @@ fill_file_fields(PyFileObject *f, FILE *fp, char *name, char *mode,
        if (f->f_name == NULL || f->f_mode == NULL)
                return NULL;
        f->f_fp = fp;
+        f = dircheck(f);
        return (PyObject *) f;
 }
 
@@ -130,6 +157,7 @@ open_the_file(PyFileObject *f, char *name, char *mode)
                        PyErr_SetFromErrnoWithFilename(PyExc_IOError, name);
                f = NULL;
        }
+        f = dircheck(f);
        return (PyObject *)f;
 }