Simplify and fix error handling for most cases.
Many functions used a local variable called return_error, which was initialized to zero. If an error occurred, it was set to true. Most of the code paths checked were only executed if return_error was false. goto is clearer. The code also seemed to be written under the curious assumption that calling Py_DECREF() on a local variable would assign the variable to NULL. As a result, more of the error-exit code paths returned an object that had a reference count of zero instead of just returning NULL. Fixed the code to explicitly assign NULL after the DECREF. A bit more reformatting, but not much. XXX Need a much better test suite for zlib, since it the current tests don't exercise any of this broken code.
This commit is contained in:
Jeremy Hylton
parent
61acf067ac
commit
9d620d018c
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@ -136,7 +136,6 @@ PyZlib_compress(PyObject *self, PyObject *args)
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Byte *input, *output;
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int length, level=Z_DEFAULT_COMPRESSION, err;
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z_stream zst;
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int return_error;
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PyObject * inputString;
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/* require Python string object, optional 'level' arg */
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@ -150,8 +149,7 @@ PyZlib_compress(PyObject *self, PyObject *args)
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zst.avail_out = length + length/1000 + 12 + 1;
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output = (Byte*)malloc(zst.avail_out);
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if (output==NULL)
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{
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if (output == NULL) {
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PyErr_SetString(PyExc_MemoryError,
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"Can't allocate memory to compress data");
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return NULL;
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@ -169,28 +167,23 @@ PyZlib_compress(PyObject *self, PyObject *args)
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zst.avail_in = length;
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err = deflateInit(&zst, level);
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return_error = 0;
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switch(err)
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{
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switch(err) {
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case(Z_OK):
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break;
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case(Z_MEM_ERROR):
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PyErr_SetString(PyExc_MemoryError,
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"Out of memory while compressing data");
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return_error = 1;
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break;
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goto error;
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case(Z_STREAM_ERROR):
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PyErr_SetString(ZlibError,
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"Bad compression level");
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return_error = 1;
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break;
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goto error;
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default:
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deflateEnd(&zst);
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zlib_error(zst, err, "while compressing data");
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return_error = 1;
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goto error;
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}
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if (!return_error) {
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Py_BEGIN_ALLOW_THREADS;
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err = deflate(&zst, Z_FINISH);
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Py_END_ALLOW_THREADS;
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@ -198,19 +191,17 @@ PyZlib_compress(PyObject *self, PyObject *args)
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if (err != Z_STREAM_END) {
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zlib_error(zst, err, "while compressing data");
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deflateEnd(&zst);
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return_error = 1;
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goto error;
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}
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if (!return_error) {
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err=deflateEnd(&zst);
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if (err == Z_OK)
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ReturnVal = PyString_FromStringAndSize((char *)output,
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zst.total_out);
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else
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zlib_error(zst, err, "while finishing compression");
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}
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}
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error:
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free(output);
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Py_DECREF(inputString);
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@ -231,7 +222,6 @@ PyZlib_decompress(PyObject *self, PyObject *args)
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int length, err;
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int wsize=DEF_WBITS, r_strlen=DEFAULTALLOC;
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z_stream zst;
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int return_error;
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PyObject * inputString;
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if (!PyArg_ParseTuple(args, "S|ii:decompress",
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@ -260,24 +250,20 @@ PyZlib_decompress(PyObject *self, PyObject *args)
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zst.next_in = (Byte *)input;
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err = inflateInit2(&zst, wsize);
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return_error = 0;
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switch(err) {
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case(Z_OK):
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break;
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case(Z_MEM_ERROR):
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PyErr_SetString(PyExc_MemoryError,
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"Out of memory while decompressing data");
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return_error = 1;
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goto error;
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default:
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inflateEnd(&zst);
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zlib_error(zst, err, "while preparing to decompress data");
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return_error = 1;
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goto error;
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}
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do {
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if (return_error)
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break;
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Py_BEGIN_ALLOW_THREADS
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err=inflate(&zst, Z_FINISH);
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Py_END_ALLOW_THREADS
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@ -295,8 +281,7 @@ PyZlib_decompress(PyObject *self, PyObject *args)
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PyErr_Format(ZlibError, "Error %i while decompressing data",
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err);
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inflateEnd(&zst);
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return_error = 1;
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break;
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goto error;
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}
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/* fall through */
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case(Z_OK):
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@ -304,7 +289,7 @@ PyZlib_decompress(PyObject *self, PyObject *args)
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if (_PyString_Resize(&result_str, r_strlen << 1) == -1) {
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inflateEnd(&zst);
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result_str = NULL;
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return_error = 1;
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goto error;
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}
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zst.next_out = (unsigned char *)PyString_AsString(result_str) \
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+ r_strlen;
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@ -314,25 +299,24 @@ PyZlib_decompress(PyObject *self, PyObject *args)
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default:
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inflateEnd(&zst);
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zlib_error(zst, err, "while decompressing data");
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return_error = 1;
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goto error;
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}
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} while (err != Z_STREAM_END);
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if (!return_error) {
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err = inflateEnd(&zst);
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if (err != Z_OK) {
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zlib_error(zst, err, "while finishing data decompression");
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return NULL;
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}
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}
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if (!return_error)
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_PyString_Resize(&result_str, zst.total_out);
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else
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Py_XDECREF(result_str); /* sets result_str == NULL, if not already */
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Py_DECREF(inputString);
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return result_str;
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error:
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Py_DECREF(inputString);
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Py_XDECREF(result_str);
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return NULL;
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}
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static PyObject *
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@ -363,8 +347,7 @@ PyZlib_compressobj(PyObject *selfptr, PyObject *args)
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return NULL;
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case(Z_STREAM_ERROR):
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Py_DECREF(self);
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PyErr_SetString(PyExc_ValueError,
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"Invalid initialization option");
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PyErr_SetString(PyExc_ValueError, "Invalid initialization option");
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return NULL;
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default:
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zlib_error(self->zst, err, "while creating compression object");
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@ -393,8 +376,7 @@ PyZlib_decompressobj(PyObject *selfptr, PyObject *args)
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return (PyObject*)self;
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case(Z_STREAM_ERROR):
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Py_DECREF(self);
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PyErr_SetString(PyExc_ValueError,
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"Invalid initialization option");
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PyErr_SetString(PyExc_ValueError, "Invalid initialization option");
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return NULL;
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case (Z_MEM_ERROR):
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Py_DECREF(self);
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@ -451,11 +433,11 @@ PyZlib_objcompress(compobject *self, PyObject *args)
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PyObject *RetVal;
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Byte *input;
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unsigned long start_total_out;
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int return_error;
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PyObject *inputString;
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if (!PyArg_ParseTuple(args, "S:compress", &inputString))
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return NULL;
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if (PyString_AsStringAndSize(inputString, (char**)&input, &inplen) == -1)
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return NULL;
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@ -476,14 +458,12 @@ PyZlib_objcompress(compobject *self, PyObject *args)
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err = deflate(&(self->zst), Z_NO_FLUSH);
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Py_END_ALLOW_THREADS
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return_error = 0;
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/* while Z_OK and the output buffer is full, there might be more output,
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so extend the output buffer and try again */
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while (err == Z_OK && self->zst.avail_out == 0) {
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if (_PyString_Resize(&RetVal, length << 1) == -1) {
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return_error = 1;
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break;
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RetVal = NULL;
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goto error;
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}
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self->zst.next_out = (unsigned char *)PyString_AsString(RetVal) \
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+ length;
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@ -499,29 +479,19 @@ PyZlib_objcompress(compobject *self, PyObject *args)
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condition.
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*/
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if (!return_error) {
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if (err != Z_OK && err != Z_BUF_ERROR) {
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if (self->zst.msg == Z_NULL)
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PyErr_Format(ZlibError, "Error %i while compressing",
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err);
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else
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PyErr_Format(ZlibError, "Error %i while compressing: %.200s",
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err, self->zst.msg);
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return_error = 1;
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zlib_error(self->zst, err, "while compressing");
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Py_DECREF(RetVal);
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RetVal = NULL;
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goto error;
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}
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}
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if (return_error)
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RetVal = NULL; /* should have been handled by DECREF */
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else
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_PyString_Resize(&RetVal, self->zst.total_out - start_total_out);
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if (_PyString_Resize(&RetVal,
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self->zst.total_out - start_total_out) < 0)
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RetVal = NULL;
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error:
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Py_DECREF(inputString);
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LEAVE_ZLIB
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return RetVal;
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}
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@ -544,7 +514,6 @@ PyZlib_objdecompress(compobject *self, PyObject *args)
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PyObject *RetVal;
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Byte *input;
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unsigned long start_total_out;
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int return_error;
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PyObject * inputString;
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if (!PyArg_ParseTuple(args, "S|i:decompress", &inputString, &max_length))
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@ -565,7 +534,6 @@ PyZlib_objdecompress(compobject *self, PyObject *args)
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return NULL;
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ENTER_ZLIB
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return_error = 0;
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Py_INCREF(inputString);
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@ -596,8 +564,8 @@ PyZlib_objdecompress(compobject *self, PyObject *args)
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length = max_length;
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if (_PyString_Resize(&RetVal, length) == -1) {
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return_error = 1;
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break;
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RetVal = NULL;
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goto error;
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}
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self->zst.next_out = (unsigned char *)PyString_AsString(RetVal) \
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+ old_length;
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@ -614,8 +582,11 @@ PyZlib_objdecompress(compobject *self, PyObject *args)
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Py_DECREF(self->unconsumed_tail);
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self->unconsumed_tail = PyString_FromStringAndSize(self->zst.next_in,
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self->zst.avail_in);
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if(!self->unconsumed_tail)
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return_error = 1;
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if(!self->unconsumed_tail) {
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Py_DECREF(RetVal);
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RetVal = NULL;
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goto error;
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}
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}
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/* The end of the compressed data has been reached, so set the
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@ -624,37 +595,29 @@ PyZlib_objdecompress(compobject *self, PyObject *args)
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inflateEnd, but the old behaviour of only calling it on flush() is
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preserved.
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*/
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if (!return_error) {
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if (err == Z_STREAM_END) {
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Py_XDECREF(self->unused_data); /* Free original empty string */
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self->unused_data = PyString_FromStringAndSize(
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(char *)self->zst.next_in, self->zst.avail_in);
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if (self->unused_data == NULL) {
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Py_DECREF(RetVal);
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return_error = 1;
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goto error;
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}
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/* We will only get Z_BUF_ERROR if the output buffer was full
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but there wasn't more output when we tried again, so it is
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not an error condition.
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*/
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} else if (err != Z_OK && err != Z_BUF_ERROR) {
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if (self->zst.msg == Z_NULL)
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PyErr_Format(ZlibError, "Error %i while decompressing",
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err);
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else
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PyErr_Format(ZlibError, "Error %i while decompressing: %.200s",
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err, self->zst.msg);
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zlib_error(self->zst, err, "while decompressing");
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Py_DECREF(RetVal);
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return_error = 1;
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}
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RetVal = NULL;
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goto error;
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}
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if (!return_error) {
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_PyString_Resize(&RetVal, self->zst.total_out - start_total_out);
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}
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else
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RetVal = NULL; /* should be handled by DECREF */
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if (_PyString_Resize(&RetVal, self->zst.total_out - start_total_out) < 0)
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RetVal = NULL;
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error:
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Py_DECREF(inputString);
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LEAVE_ZLIB
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@ -677,7 +640,6 @@ PyZlib_flush(compobject *self, PyObject *args)
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PyObject *RetVal;
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int flushmode = Z_FINISH;
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unsigned long start_total_out;
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int return_error;
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if (!PyArg_ParseTuple(args, "|i:flush", &flushmode))
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return NULL;
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@ -702,14 +664,12 @@ PyZlib_flush(compobject *self, PyObject *args)
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err = deflate(&(self->zst), flushmode);
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Py_END_ALLOW_THREADS
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return_error = 0;
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/* while Z_OK and the output buffer is full, there might be more output,
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so extend the output buffer and try again */
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while (err == Z_OK && self->zst.avail_out == 0) {
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if (_PyString_Resize(&RetVal, length << 1) == -1) {
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return_error = 1;
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break;
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RetVal = NULL;
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goto error;
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}
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self->zst.next_out = (unsigned char *)PyString_AsString(RetVal) \
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+ length;
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@ -724,21 +684,15 @@ PyZlib_flush(compobject *self, PyObject *args)
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/* If flushmode is Z_FINISH, we also have to call deflateEnd() to free
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various data structures. Note we should only get Z_STREAM_END when
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flushmode is Z_FINISH, but checking both for safety*/
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if (!return_error) {
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if (err == Z_STREAM_END && flushmode == Z_FINISH) {
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err = deflateEnd(&(self->zst));
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if (err != Z_OK) {
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if (self->zst.msg == Z_NULL)
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PyErr_Format(ZlibError, "Error %i from deflateEnd()",
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err);
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else
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PyErr_Format(ZlibError,
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"Error %i from deflateEnd(): %.200s",
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err, self->zst.msg);
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zlib_error(self->zst, err, "from deflateEnd()");
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Py_DECREF(RetVal);
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return_error = 1;
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} else
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RetVal = NULL;
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goto error;
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||||
}
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||||
else
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self->is_initialised = 0;
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/* We will only get Z_BUF_ERROR if the output buffer was full
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@ -746,23 +700,16 @@ PyZlib_flush(compobject *self, PyObject *args)
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|||
not an error condition.
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*/
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} else if (err!=Z_OK && err!=Z_BUF_ERROR) {
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if (self->zst.msg == Z_NULL)
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PyErr_Format(ZlibError, "Error %i while flushing",
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err);
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else
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PyErr_Format(ZlibError, "Error %i while flushing: %.200s",
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err, self->zst.msg);
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||||
zlib_error(self->zst, err, "while flushing");
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||||
Py_DECREF(RetVal);
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||||
return_error = 1;
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||||
}
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||||
RetVal = NULL;
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||||
}
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||||
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||||
if (!return_error)
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||||
_PyString_Resize(&RetVal, self->zst.total_out - start_total_out);
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||||
else
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||||
RetVal = NULL; /* should have been handled by DECREF */
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||||
if (_PyString_Resize(&RetVal, self->zst.total_out - start_total_out) < 0)
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||||
RetVal = NULL;
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||||
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||||
LEAVE_ZLIB
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||||
error:
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||||
LEAVE_ZLIB;
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||||
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||||
return RetVal;
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||||
}
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|
|
@ -780,7 +727,7 @@ PyZlib_unflush(compobject *self, PyObject *args)
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|||
exceptions. This behaviour has been preserved.*/
|
||||
{
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||||
int err;
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||||
PyObject * retval;
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||||
PyObject * retval = NULL;
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||||
|
||||
if (!PyArg_ParseTuple(args, ""))
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||||
return NULL;
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||||
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|
@ -788,10 +735,9 @@ PyZlib_unflush(compobject *self, PyObject *args)
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|||
ENTER_ZLIB
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||||
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||||
err = inflateEnd(&(self->zst));
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||||
if (err != Z_OK) {
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||||
if (err != Z_OK)
|
||||
zlib_error(self->zst, err, "from inflateEnd()");
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||||
retval = NULL;
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||||
} else {
|
||||
else {
|
||||
self->is_initialised = 0;
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||||
retval = PyString_FromStringAndSize(NULL, 0);
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||||
}
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||||
|
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|
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