python plugin: silence -Wconversion warnings.

plugins/python/pyhelpers.c

@@ -205,7 +205,7 @@ py_str_array_from_tuple(PyObject *py_tuple)
     Py_ssize_t tuple_size = PyTuple_Size(py_tuple);
 
     // we need an extra 0 at the end
-    char **result = calloc(tuple_size + 1, sizeof(char *));
+    char **result = calloc((size_t)tuple_size + 1, sizeof(char *));
     if (result == NULL) {
         debug_return_ptr(NULL);
     }

plugins/python/python_convmessage.c

@@ -137,7 +137,7 @@ sudo_module_ConvMessages_to_c(PyObject *py_tuple, Py_ssize_t *num_msgs, struct s
         debug_return_int(SUDO_RC_ERROR);
     }
 
-    *msgs = calloc(*num_msgs, sizeof(struct sudo_conv_message));
+    *msgs = calloc((size_t)*num_msgs, sizeof(struct sudo_conv_message));
     if (*msgs == NULL) {
         debug_return_int(SUDO_RC_ERROR);
     }

plugins/python/regress/iohelpers.c

@@ -149,7 +149,7 @@ str_replaced(const char *source, size_t dest_len, const char *old, const char *n
         return NULL;
 
     while ((pos = strstr(source, old)) != NULL) {
-        size_t len = snprintf(dest, dest_len,
+        size_t len = (size_t)snprintf(dest, dest_len,
             "%.*s%s", (int)(pos - source), source, new);
         if (len >= dest_len)
             goto fail;

plugins/python/regress/testhelpers.c

@@ -42,7 +42,7 @@ remove_underline(char *output)
 	size_t len = strspn(cp, "^ \t");
 	if (len > 0 && cp[len] == '\n') {
 	    /* Prune out lines that are "underlining". */
-	    memmove(cp, cp + len + 1, ep - cp);
+	    memmove(cp, cp + len + 1, (size_t)(ep - cp));
 	    if (*cp == '\0')
 		break;
 	} else {
@@ -238,8 +238,10 @@ verify_log_lines(const char *reference_path)
         line_data += 2;
 
         char *line_end = strstr(line_data, " object at "); // this skips checking the pointer hex
-        if (line_end)
-            snprintf(line_end, sizeof(line) - (line_end - line), " object>\n");
+        if (line_end) {
+            snprintf(line_end, sizeof(line) - (size_t)(line_end - line),
+		" object>\n");
+	}
 
 	if (strncmp(line_data, "handle @ /", sizeof("handle @ /") - 1) == 0) {
             char *start = line_data + sizeof("handle @ ") - 1;

plugins/python/sudo_python_module.c

@@ -351,7 +351,7 @@ python_sudo_conversation(PyObject *Py_UNUSED(self), PyObject *py_args, PyObject
         goto cleanup;
     }
 
-    replies = calloc(num_msgs, sizeof(struct sudo_conv_reply));
+    replies = calloc((size_t)num_msgs, sizeof(struct sudo_conv_reply));
     if (replies == NULL)
         goto cleanup;
     py_result = PyTuple_New(num_msgs);