From 3f4c1cce77cbe1337e5642e9e0e9d048c9e07370 Mon Sep 17 00:00:00 2001
From: Alexey Sokolov <alexey+znc@asokolov.org>
Date: Fri, 5 Jan 2024 02:19:55 +0000
Subject: [PATCH] Fix build with SWIG 4.2.0

https://bugs.gentoo.org/921230
---
 modules/modpython/codegen.pl | 88 ++++++++++++++++++++++++++----------
 1 file changed, 65 insertions(+), 23 deletions(-)

diff --git a/modules/modpython/codegen.pl b/modules/modpython/codegen.pl
index 1bc09806e0..bbcb148bed 100755
--- a/modules/modpython/codegen.pl
+++ b/modules/modpython/codegen.pl
@@ -50,29 +50,6 @@
  ***************************************************************************/
 
 namespace {
-/*	template<class T>
-	struct pyobj_to_ptr {
-		CString m_sType;
-		SvToPtr(const CString& sType) {
-			m_sType = sType;
-		}
-		bool operator()(PyObject* py, T** result) {
-			T* x = nullptr;
-			int res = SWIG_ConvertPtr(sv, (void**)&x, SWIG_TypeQuery(m_sType.c_str()), 0);
-			if (SWIG_IsOK(res)) {
-				*result = x;
-				return true;
-			}
-			DEBUG("modpython: ");
-			return false;
-		}
-	};
-
-	CModule::EModRet SvToEModRet(PyObject* py, CModule::EModRet* result) {
-		long int x = PyLong_AsLong();
-		return static_cast<CModule::EModRet>(SvUV(sv));
-	}*/
-
 	inline swig_type_info* SWIG_pchar_descriptor(void) {
 		static int init = 0;
 		static swig_type_info* info = 0;
@@ -83,6 +60,70 @@
 		return info;
 	}
 
+// SWIG 4.2.0 replaced SWIG_Python_str_AsChar with SWIG_PyUnicode_AsUTF8AndSize.
+// SWIG doesn't provide any good way to detect SWIG version (other than parsing
+// `swig -version`), but it also introduced SWIG_NULLPTR.
+// So let's abuse that define to do different code for new SWIG.
+#ifdef SWIG_NULLPTR
+	// This is copied from some SWIG 4.2.0 from pystrings.swg
+	inline int SWIG_AsCharPtrAndSize(PyObject *obj, char** cptr, size_t* psize, int *alloc) {
+#if PY_VERSION_HEX>=0x03000000
+#if defined(SWIG_PYTHON_STRICT_BYTE_CHAR)
+		if (PyBytes_Check(obj))
+#else
+		if (PyUnicode_Check(obj))
+#endif
+#else
+		if (PyString_Check(obj))
+#endif
+		{
+			char *cstr; Py_ssize_t len;
+			PyObject *bytes = NULL;
+			int ret = SWIG_OK;
+			if (alloc)
+				*alloc = SWIG_OLDOBJ;
+#if PY_VERSION_HEX>=0x03000000 && defined(SWIG_PYTHON_STRICT_BYTE_CHAR)
+			if (PyBytes_AsStringAndSize(obj, &cstr, &len) == -1)
+				return SWIG_TypeError;
+#else
+			cstr = (char *)SWIG_PyUnicode_AsUTF8AndSize(obj, &len, &bytes);
+			if (!cstr)
+				return SWIG_TypeError;
+			/* The returned string is only duplicated if the char * returned is not owned and memory managed by obj */
+			if (bytes && cptr) {
+				if (alloc) {
+					//cstr = %new_copy_array(cstr, len + 1, char);
+					cstr = (char *)memcpy((char *)malloc((len + 1)*sizeof(char)), cstr, sizeof(char)*(len + 1));
+					*alloc = SWIG_NEWOBJ;
+				} else {
+					/* alloc must be set in order to clean up allocated memory */
+					return SWIG_RuntimeError;
+				}
+			}
+#endif
+			if (cptr) *cptr = cstr;
+			if (psize) *psize = len + 1;
+			Py_XDECREF(bytes);
+			return ret;
+		} else {
+			swig_type_info* pchar_descriptor = SWIG_pchar_descriptor();
+			if (pchar_descriptor) {
+				void* vptr = 0;
+				if (SWIG_ConvertPtr(obj, &vptr, pchar_descriptor, 0) == SWIG_OK) {
+					if (cptr) *cptr = (char *) vptr;
+					if (psize) *psize = vptr ? (strlen((char *)vptr) + 1) : 0;
+					if (alloc) *alloc = SWIG_OLDOBJ;
+					return SWIG_OK;
+				}
+			}
+		}
+		return SWIG_TypeError;
+	}
+
+#else
+	// TODO: at some point drop support for SWIG<4.2.0 (drop this branch of ifdef)
+
+	// This is copied from some old SWIG version from pystrings.swg
 	inline int SWIG_AsCharPtrAndSize(PyObject *obj, char** cptr, size_t* psize, int *alloc) {
 #if PY_VERSION_HEX>=0x03000000
 		if (PyUnicode_Check(obj))
@@ -155,6 +196,7 @@
 			}
 		return SWIG_TypeError;
 	}
+#endif
 
 	inline int SWIG_AsPtr_CString (PyObject * obj, CString **val) {
 		char* buf = 0 ; size_t size = 0; int alloc = SWIG_OLDOBJ;