diff --git a/Lib/test/test_file.py b/Lib/test/test_file.py index ba6ea47edf7..830871098e1 100644 --- a/Lib/test/test_file.py +++ b/Lib/test/test_file.py @@ -355,6 +355,48 @@ class StdoutTests(unittest.TestCase): finally: sys.stdout = save_stdout + def testReadAfterEOF(self): + # Regression test for SF bug #1523853. + # Verify read works after hitting EOF + + # Prepare the testfile + teststring = "spam" + bag = open(TESTFN, "w") + bag.write(teststring) + bag.close() + + # And buf for readinto + buf = array("c", " "*len(teststring)) + + # Test for appropriate errors mixing read* and iteration + methods = [("readline", ()), ("read",()), ("readlines", ()), + ("readinto", (buf,))] + + for attr in 'r', 'rU': + for methodname, args in methods: + f = open(TESTFN, "rU") + f.seek(0, 2) + meth = getattr(f, methodname) + meth(*args) # hits EOF + try: + # Writing the same file with another file descriptor + append = open(TESTFN, "a+") + append.write(teststring) + append.flush() + append.close() + try: + meth = getattr(f, methodname) + if methodname == 'readlines': + self.failUnlessEqual(meth(*args), [teststring]) + elif methodname == 'readinto': + meth(*args) + self.failUnlessEqual(buf.tostring(), teststring) + else: + self.failUnlessEqual(meth(*args), teststring) + except ValueError: + self.fail("read* failed after hitting EOF") + finally: + f.close() def test_main(): # Historically, these tests have been sloppy about removing TESTFN. diff --git a/Misc/NEWS b/Misc/NEWS index fa5ceb6fc45..18af6d09f4d 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -12,6 +12,9 @@ What's New in Python 2.5.3? Core and builtins ----------------- +- Issue #1706039: Support continued reading from a file even after + EOF was hit. + - Issue #1683: prevent forking from interfering in threading storage. - Issue #4597: Fixed several opcodes that weren't always propagating diff --git a/Objects/fileobject.c b/Objects/fileobject.c index 565bf5ca2f7..5b76b0d0cc6 100644 --- a/Objects/fileobject.c +++ b/Objects/fileobject.c @@ -861,16 +861,16 @@ file_read(PyFileObject *f, PyObject *args) buffersize - bytesread, f->f_fp, (PyObject *)f); Py_END_ALLOW_THREADS if (chunksize == 0) { - if (!ferror(f->f_fp)) + if (!PyErr_ExceptionMatches(PyExc_IOError)) break; - clearerr(f->f_fp); /* When in non-blocking mode, data shouldn't * be discarded if a blocking signal was * received. That will also happen if * chunksize != 0, but bytesread < buffersize. */ - if (bytesread > 0 && BLOCKED_ERRNO(errno)) + if (bytesread > 0 && BLOCKED_ERRNO(errno)) { + PyErr_Clear(); break; - PyErr_SetFromErrno(PyExc_IOError); + } Py_DECREF(v); return NULL; } @@ -917,10 +917,8 @@ file_readinto(PyFileObject *f, PyObject *args) (PyObject *)f); Py_END_ALLOW_THREADS if (nnow == 0) { - if (!ferror(f->f_fp)) + if (!PyErr_ExceptionMatches(PyExc_IOError)) break; - PyErr_SetFromErrno(PyExc_IOError); - clearerr(f->f_fp); return NULL; } ndone += nnow; @@ -1412,10 +1410,8 @@ file_readlines(PyFileObject *f, PyObject *args) } if (nread == 0) { sizehint = 0; - if (!ferror(f->f_fp)) + if (!PyErr_ExceptionMatches(PyExc_IOError)) break; - PyErr_SetFromErrno(PyExc_IOError); - clearerr(f->f_fp); error: Py_DECREF(list); list = NULL; @@ -1863,9 +1859,7 @@ readahead(PyFileObject *f, int bufsize) f->f_buf, bufsize, f->f_fp, (PyObject *)f); Py_END_ALLOW_THREADS if (chunksize == 0) { - if (ferror(f->f_fp)) { - PyErr_SetFromErrno(PyExc_IOError); - clearerr(f->f_fp); + if (PyErr_ExceptionMatches(PyExc_IOError)) { drop_readahead(f); return -1; } @@ -2416,6 +2410,7 @@ Py_UniversalNewlineFread(char *buf, size_t n, char *dst = buf; PyFileObject *f = (PyFileObject *)fobj; int newlinetypes, skipnextlf; + size_t nread; assert(buf != NULL); assert(stream != NULL); @@ -2424,22 +2419,35 @@ Py_UniversalNewlineFread(char *buf, size_t n, errno = ENXIO; /* What can you do... */ return 0; } - if (!f->f_univ_newline) - return fread(buf, 1, n, stream); + if (!f->f_univ_newline) { + nread = fread(buf, 1, n, stream); + if (nread == 0) { + if (ferror(stream)) + PyErr_SetFromErrno(PyExc_IOError); + clearerr(stream); + } + return nread; + } newlinetypes = f->f_newlinetypes; skipnextlf = f->f_skipnextlf; /* Invariant: n is the number of bytes remaining to be filled * in the buffer. */ while (n) { - size_t nread; int shortread; char *src = dst; nread = fread(dst, 1, n, stream); assert(nread <= n); - if (nread == 0) + if (nread == 0) { + if (ferror(stream)) { + clearerr(stream); + PyErr_SetFromErrno(PyExc_IOError); + return 0; + } + clearerr(stream); break; + } n -= nread; /* assuming 1 byte out for each in; will adjust */ shortread = n != 0; /* true iff EOF or error */