gplugin/gplugin

fix memory leaks in gplugin_file_source

14 months ago, Markus Fischer
d821f171d4c6
fix memory leaks in gplugin_file_source

leaks encountered:
## libpurple test_contact_info and test_person
```
==5998== 16 bytes in 1 blocks are definitely lost in loss record 1,996 of 6,277
==5998== at 0x48417E4: malloc (vg_replace_malloc.c:393)
==5998== by 0x4A6FA18: g_malloc (in /usr/lib64/libglib-2.0.so.0.7400.4)
==5998== by 0x4A88540: g_slice_alloc (in /usr/lib64/libglib-2.0.so.0.7400.4)
==5998== by 0x4A89675: g_slist_prepend (in /usr/lib64/libglib-2.0.so.0.7400.4)
==5998== by 0x4F0DA9E: gplugin_file_source_add_loader (gplugin-file-source.c:112)
==5998== by 0x4F0DCF1: gplugin_file_source_update_loaders (gplugin-file-source.c:179)
==5998== by 0x4F0E971: gplugin_file_source_constructed (gplugin-file-source.c:524)
==5998== by 0x49CF002: ??? (in /usr/lib64/libgobject-2.0.so.0.7400.4)
==5998== by 0x49D0C33: g_object_new_valist (in /usr/lib64/libgobject-2.0.so.0.7400.4)
==5998== by 0x49D1250: g_object_new (in /usr/lib64/libgobject-2.0.so.0.7400.4)
==5998== by 0x4F0EC51: gplugin_file_source_new (gplugin-file-source.c:607)
==5998== by 0x4F08019: gplugin_manager_refresh (gplugin-manager.c:874)
```
## gplugin tests
```
==23357== 456 (16 direct, 440 indirect) bytes in 1 blocks are definitely lost in loss record 535 of 557
==23357== at 0x48417E4: malloc (vg_replace_malloc.c:393)
==23357== by 0x48E4828: g_malloc (in /usr/lib64/libglib-2.0.so.0.7400.5)
==23357== by 0x48FD281: g_slice_alloc (in /usr/lib64/libglib-2.0.so.0.7400.5)
==23357== by 0x48FE6A8: g_slist_copy_deep (in /usr/lib64/libglib-2.0.so.0.7400.5)
==23357== by 0x485B252: gplugin_manager_find_plugins (gplugin-manager.c:934)
==23357== by 0x4861216: gplugin_file_source_scan (gplugin-file-source.c:349)
==23357== by 0x48622A9: gplugin_source_scan (gplugin-source.c:66)
==23357== by 0x485B041: gplugin_manager_refresh (gplugin-manager.c:881)
==23357== by 0x109464: test_gplugin_init_uninit_with_double_refresh_plugins (test-core.c:115)
==23357== by 0x49079DD: ??? (in /usr/lib64/libglib-2.0.so.0.7400.5)
==23357== by 0x490774C: ??? (in /usr/lib64/libglib-2.0.so.0.7400.5)
==23357== by 0x4907EE1: g_test_run_suite (in /usr/lib64/libglib-2.0.so.0.7400.5)
```

Testing Done:
Ran all gplugin tests and test_contact_info and test_person from libpurple in valgrind without encountering above leaks or any invalid reads/writes.

Reviewed at https://reviews.imfreedom.org/r/2255/
/*
* Copyright (C) 2011-2020 Gary Kramlich <grim@reaperworld.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <https://www.gnu.org/licenses/>.
*/
#define PY_SSIZE_T_CLEAN
#include <Python.h>
#include "gplugin-python3-utils.h"
#include <gplugin.h>
gchar *
gplugin_python3_filename_to_module(const gchar *filename)
{
gchar *base = NULL;
gchar *e = NULL, *r = NULL;
g_return_val_if_fail(filename != NULL, NULL);
/* first make sure we just have a filename */
base = g_path_get_basename(filename);
/* now find the last . for the extension */
e = g_utf8_strrchr(base, -1, g_utf8_get_char("."));
if(e == NULL) {
return base;
}
/* now copy the module name into r */
r = g_strndup(base, e - base);
/* free the basename */
g_free(base);
return r;
}
gboolean
gplugin_python3_add_module_path(const gchar *module_path)
{
PyObject *sys_path = NULL, *path = NULL;
gboolean ret = FALSE;
sys_path = PySys_GetObject("path");
path = PyUnicode_FromString(module_path);
if(PySequence_Contains(sys_path, path) == 0) {
PyList_Insert(sys_path, 0, path);
ret = TRUE;
}
Py_DECREF(path);
return ret;
}
GError *
gplugin_python3_exception_to_gerror(void)
{
GError *error = NULL;
PyObject *type = NULL, *value = NULL, *trace = NULL;
PyObject *type_name = NULL, *value_str = NULL, *obj = NULL;
if(!PyErr_Occurred()) {
return NULL;
}
PyErr_Fetch(&type, &value, &trace);
if(type == NULL) {
return NULL;
}
PyErr_NormalizeException(&type, &value, &trace);
Py_XDECREF(trace);
type_name = PyObject_GetAttrString(type, "__name__");
Py_DECREF(type);
value_str = PyObject_Str(value);
Py_DECREF(value);
/* now decode the utf8 into a string we can use */
obj = PyUnicode_AsUTF8String(type_name);
Py_DECREF(type_name);
type_name = obj;
obj = PyUnicode_AsUTF8String(value_str);
Py_DECREF(value_str);
value_str = obj;
error = g_error_new(
GPLUGIN_DOMAIN,
0,
"%s: %s",
PyBytes_AsString(type_name),
PyBytes_AsString(value_str));
Py_DECREF(type_name);
Py_DECREF(value_str);
return error;
}