curl: error out if wolfSSL is not usable

When we explicitly declare, that we would like to have curl built with
wolfSSL support using `--with-wolfssl` configure option, then we should
make sure, that we either endup with curl having that support, or it
shouldn't be available at all, otherwise we risk, that we end up with
regressions like following:

  configure:25299: checking for wolfSSL_Init in -lwolfssl
  configure:25321: x86_64-openwrt-linux-musl-gcc -o conftest [snip]
  In file included from target-x86_64_musl/usr/include/wolfssl/wolfcrypt/dsa.h:33,
                   from target-x86_64_musl/usr/include/wolfssl/wolfcrypt/asn_public.h:35,
                  from target-x86_64_musl/usr/include/wolfssl/ssl.h:35,
                   from conftest.c:47:
  target-x86_64_musl/usr/include/wolfssl/wolfcrypt/integer.h:37:14: fatal error: wolfssl/wolfcrypt/sp_int.h: No such file or directory
       #include <wolfssl/wolfcrypt/sp_int.h>
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  compilation terminated.

and in the end thus produce curl without https support:

 curl: (1) Protocol "https" not supported or disabled in libcurl

So fix it, by making the working wolfSSL mandatory and error out in
configure step when that's not the case:

 checking for wolfSSL_Init in -lwolfssl... no
 configure: error: --with-wolfssl but wolfSSL was not found or doesn't work

References: #19005, #19547
Upstream-Status: Accepted [https://github.com/curl/curl/pull/9682]
Signed-off-by: Petr Štetiar <ynezz@true.cz>

net/curl/patches/300-curl-wolfssl.m4-error-out-if-wolfSSL-is-not-usable.patch

@@ -0,0 +1,57 @@
+From 5c91ff8853cbe08fb30462f99d3261383de9b98e Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Petr=20=C5=A0tetiar?= <ynezz@true.cz>
+Date: Mon, 10 Oct 2022 07:36:56 +0200
+Subject: [PATCH] curl-wolfssl.m4: error out if wolfSSL is not usable
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+When I explicitly declare, that I would like to have curl built with
+wolfSSL support using `--with-wolfssl` configure option, then I would
+expect, that either I endup with curl having that support, for example
+in form of https support or it wouldn't be available at all.
+
+Downstream projects like for example OpenWrt build curl wolfSSL variant
+with `--with-wolfssl` already, but in certain corner cases it does fail:
+
+  configure:25299: checking for wolfSSL_Init in -lwolfssl
+  configure:25321: x86_64-openwrt-linux-musl-gcc -o conftest [snip]
+  In file included from target-x86_64_musl/usr/include/wolfssl/wolfcrypt/dsa.h:33,
+                   from target-x86_64_musl/usr/include/wolfssl/wolfcrypt/asn_public.h:35,
+                  from target-x86_64_musl/usr/include/wolfssl/ssl.h:35,
+                   from conftest.c:47:
+  target-x86_64_musl/usr/include/wolfssl/wolfcrypt/integer.h:37:14: fatal error: wolfssl/wolfcrypt/sp_int.h: No such file or directory
+       #include <wolfssl/wolfcrypt/sp_int.h>
+                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
+  compilation terminated.
+
+and in the end thus produces curl without https support:
+
+ curl: (1) Protocol "https" not supported or disabled in libcurl
+
+So fix it, by making the working wolfSSL mandatory and error out in
+configure step when that's not the case:
+
+ checking for wolfSSL_Init in -lwolfssl... no
+ configure: error: --with-wolfssl but wolfSSL was not found or doesn't work
+
+References: https://github.com/openwrt/packages/issues/19005
+References: https://github.com/openwrt/packages/issues/19547
+Upstream-Status: Accepted [https://github.com/curl/curl/pull/9682]
+Signed-off-by: Petr Štetiar <ynezz@true.cz>
+---
+ m4/curl-wolfssl.m4 | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/m4/curl-wolfssl.m4
++++ b/m4/curl-wolfssl.m4
+@@ -154,7 +154,8 @@ if test "x$OPT_WOLFSSL" != xno; then
+           AC_MSG_NOTICE([Added $wolfssllibpath to CURL_LIBRARY_PATH])
+         fi
+       fi
+-
++    else
++        AC_MSG_ERROR([--with-wolfssl but wolfSSL was not found or doesn't work])
+     fi
+ 
+   fi dnl wolfSSL not disabled