Added the const qualifier to char* variables that refer to readonly internal

UTF-8 represenatation of Unicode objects.

Modules/_ctypes/_ctypes.c

@@ -1829,7 +1829,7 @@ static PyCArgObject *
 PyCSimpleType_paramfunc(CDataObject *self)
 {
     StgDictObject *dict;
-    char *fmt;
+    const char *fmt;
     PyCArgObject *parg;
     struct fielddesc *fd;
 
@@ -2039,7 +2039,7 @@ static PyObject *
 PyCSimpleType_from_param(PyObject *type, PyObject *value)
 {
     StgDictObject *dict;
-    char *fmt;
+    const char *fmt;
     PyCArgObject *parg;
     struct fielddesc *fd;
     PyObject *as_parameter;

Modules/_ctypes/stgdict.c

@@ -488,8 +488,8 @@ PyCStructUnionType_update_stgdict(PyObject *type, PyObject *fields, int isStruct
             bitsize = 0;
 
         if (isStruct && !isPacked) {
-            char *fieldfmt = dict->format ? dict->format : "B";
-            char *fieldname = PyUnicode_AsUTF8(name);
+            const char *fieldfmt = dict->format ? dict->format : "B";
+            const char *fieldname = PyUnicode_AsUTF8(name);
             char *ptr;
             Py_ssize_t len;
             char *buf;

Modules/_elementtree.c

@@ -3613,7 +3613,7 @@ _elementtree_XMLParser__setevents_impl(XMLParserObject *self,
 
     for (i = 0; i < PySequence_Size(events_seq); ++i) {
         PyObject *event_name_obj = PySequence_Fast_GET_ITEM(events_seq, i);
-        char *event_name = NULL;
+        const char *event_name = NULL;
         if (PyUnicode_Check(event_name_obj)) {
             event_name = PyUnicode_AsUTF8(event_name_obj);
         } else if (PyBytes_Check(event_name_obj)) {

Modules/_io/bufferedio.c

@@ -305,7 +305,7 @@ _enter_buffered_busy(buffered *self)
             "could not acquire lock for %A at interpreter "
             "shutdown, possibly due to daemon threads",
             (PyObject *) self);
-        char *msg = PyUnicode_AsUTF8(msgobj);
+        const char *msg = PyUnicode_AsUTF8(msgobj);
         Py_FatalError(msg);
     }
     return 1;

Modules/_io/stringio.c

@@ -693,7 +693,7 @@ _io_StringIO___init___impl(stringio *self, PyObject *value,
                            PyObject *newline_obj)
 /*[clinic end generated code: output=a421ea023b22ef4e input=cee2d9181b2577a3]*/
 {
-    char *newline = "\n";
+    const char *newline = "\n";
     Py_ssize_t value_len;
 
     /* Parse the newline argument. We only want to allow unicode objects or

Modules/_pickle.c

@@ -1941,7 +1941,7 @@ save_long(PicklerObject *self, PyObject *obj)
             goto error;
     }
     else {
-        char *string;
+        const char *string;
 
         /* proto < 2: write the repr and newline.  This is quadratic-time (in
            the number of digits), in both directions.  We add a trailing 'L'
@@ -2218,7 +2218,7 @@ write_unicode_binary(PicklerObject *self, PyObject *obj)
 {
     PyObject *encoded = NULL;
     Py_ssize_t size;
-    char *data;
+    const char *data;
     int r;
 
     if (PyUnicode_READY(obj))

Modules/_sqlite/connection.c

@@ -1489,7 +1489,7 @@ pysqlite_connection_create_collation(pysqlite_Connection* self, PyObject* args)
     PyObject* retval;
     Py_ssize_t i, len;
     _Py_IDENTIFIER(upper);
-    char *uppercase_name_str;
+    const char *uppercase_name_str;
     int rc;
     unsigned int kind;
     void *data;

Modules/_sqlite/row.c

@@ -79,12 +79,12 @@ PyObject* pysqlite_row_item(pysqlite_Row* self, Py_ssize_t idx)
 PyObject* pysqlite_row_subscript(pysqlite_Row* self, PyObject* idx)
 {
     Py_ssize_t _idx;
-    char* key;
+    const char *key;
     Py_ssize_t nitems, i;
-    char* compare_key;
+    const char *compare_key;
 
-    char* p1;
-    char* p2;
+    const char *p1;
+    const char *p2;
 
     PyObject* item;
 

Modules/_sqlite/statement.c

@@ -112,7 +112,7 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con
 int pysqlite_statement_bind_parameter(pysqlite_Statement* self, int pos, PyObject* parameter)
 {
     int rc = SQLITE_OK;
-    char* string;
+    const char *string;
     Py_ssize_t buflen;
     parameter_type paramtype;
 

Modules/_tkinter.c

@@ -536,7 +536,7 @@ SplitObj(PyObject *arg)
     else if (PyUnicode_Check(arg)) {
         int argc;
         const char **argv;
-        char *list = PyUnicode_AsUTF8(arg);
+        const char *list = PyUnicode_AsUTF8(arg);
 
         if (list == NULL ||
             Tcl_SplitList((Tcl_Interp *)NULL, list, &argc, &argv) != TCL_OK) {
@@ -993,7 +993,7 @@ asBignumObj(PyObject *value)
     Tcl_Obj *result;
     int neg;
     PyObject *hexstr;
-    char *hexchars;
+    const char *hexchars;
     mp_int bigValue;
 
     neg = Py_SIZE(value) < 0;
@@ -1723,7 +1723,7 @@ class varname_converter(CConverter):
 static int
 varname_converter(PyObject *in, void *_out)
 {
-    char *s;
+    const char *s;
     const char **out = (const char**)_out;
     if (PyBytes_Check(in)) {
         if (PyBytes_GET_SIZE(in) > INT_MAX) {

Modules/socketmodule.c

@@ -5982,7 +5982,7 @@ socket_getaddrinfo(PyObject *self, PyObject *args, PyObject* kwargs)
     PyObject *hobj = NULL;
     PyObject *pobj = (PyObject *)NULL;
     char pbuf[30];
-    char *hptr, *pptr;
+    const char *hptr, *pptr;
     int family, socktype, protocol, flags;
     int error;
     PyObject *all = (PyObject *)NULL;

Modules/syslogmodule.c

@@ -116,7 +116,7 @@ syslog_openlog(PyObject * self, PyObject * args, PyObject *kwds)
     long facility = LOG_USER;
     PyObject *new_S_ident_o = NULL;
     static char *keywords[] = {"ident", "logoption", "facility", 0};
-    char *ident = NULL;
+    const char *ident = NULL;
 
     if (!PyArg_ParseTupleAndKeywords(args, kwds,
                           "|Ull:openlog", keywords, &new_S_ident_o, &logopt, &facility))