--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/m4/curl-override.m4	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,75 @@
+#***************************************************************************
+#***************************************************************************
+
+# File version for 'aclocal' use. Keep it a single number.
+# serial 7
+
+dnl CURL_OVERRIDE_AUTOCONF
+dnl -------------------------------------------------
+dnl Placing a call to this macro in configure.ac after
+dnl the one to AC_INIT will make macros in this file
+dnl visible to the rest of the compilation overriding
+dnl those from Autoconf.
+
+AC_DEFUN([CURL_OVERRIDE_AUTOCONF], [
+AC_BEFORE([$0],[AC_PROG_LIBTOOL])
+# using curl-override.m4
+])
+
+dnl Override Autoconf's AC_LANG_PROGRAM (C)
+dnl -------------------------------------------------
+dnl This is done to prevent compiler warning
+dnl 'function declaration isn't a prototype'
+dnl in function main. This requires at least
+dnl a c89 compiler and does not support K&R.
+
+m4_define([AC_LANG_PROGRAM(C)],
+[$1
+int main (void)
+{
+$2
+ ;
+ return 0;
+}])
+
+dnl Override Autoconf's AC_LANG_CALL (C)
+dnl -------------------------------------------------
+dnl This is a backport of Autoconf's 2.60 with the
+dnl embedded comments that hit the resulting script
+dnl removed. This is done to reduce configure size
+dnl and use fixed macro across Autoconf versions.
+
+m4_define([AC_LANG_CALL(C)],
+[AC_LANG_PROGRAM([$1
+m4_if([$2], [main], ,
+[
+#ifdef __cplusplus
+extern "C"
+#endif
+char $2 ();])], [return $2 ();])])
+
+dnl Override Autoconf's AC_LANG_FUNC_LINK_TRY (C)
+dnl -------------------------------------------------
+dnl This is a backport of Autoconf's 2.60 with the
+dnl embedded comments that hit the resulting script
+dnl removed. This is done to reduce configure size
+dnl and use fixed macro across Autoconf versions.
+
+m4_define([AC_LANG_FUNC_LINK_TRY(C)],
+[AC_LANG_PROGRAM(
+[
+#define $1 innocuous_$1
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+#undef $1
+#ifdef __cplusplus
+extern "C"
+#endif
+char $1 ();
+#if defined __stub_$1 || defined __stub___$1
+choke me
+#endif
+], [return $1 ();])])