Review conf_net.py: fix socket extra_libs and getaddrinfo ipv6 check.

- check_network_libs: pass extra_libs=v.LIBS when checking for -lsocket,
  matching configure.ac's AC_CHECK_LIB 5th arg ($LIBS); on SVR4/Solaris,
  socket requires -lnsl in the link test.
- check_getaddrinfo: replace v.enable_ipv6 != "" (always False, falls back
  to unset env var) with ENABLE_IPV6.given, which correctly detects whether
  --enable-ipv6 or --disable-ipv6 was explicitly passed.

Assisted-by: Claude

Author: nascheme

Tools/configure/conf_net.py

@@ -35,7 +35,7 @@ def check_network_libs(v):
     # Most SVR4 platforms (e.g. Solaris) need -lsocket and -lnsl.
     if pyconf.check_lib("nsl", "t_open"):
         v.LIBS = f"-lnsl {v.LIBS}"
-    if pyconf.check_lib("socket", "socket"):
+    if pyconf.check_lib("socket", "socket", extra_libs=v.LIBS):
         v.LIBS = f"-lsocket {v.LIBS}"
     if f"{v.ac_sys_system}/{v.ac_sys_release}".startswith("Haiku"):
         if pyconf.check_lib("network", "socket"):
@@ -380,7 +380,7 @@ def check_getaddrinfo(v):
             if pyconf.cross_compiling:
                 if v.ac_sys_system in ("Linux-android", "iOS"):
                     ac_cv_buggy_getaddrinfo = False
-                elif v.enable_ipv6 != "":
+                elif ENABLE_IPV6.given:
                     ac_cv_buggy_getaddrinfo = (
                         "no -- configured with --(en|dis)able-ipv6"
                     )

Tools/configure/configure.awk

@@ -5069,6 +5069,12 @@ function u__setup_macos_deployment_target(    _tmp_split, arch, cur_target, cur_
 
 # --- conf_math ---
 function u_check_math_library(    found, with_libc, with_libm) {
+    pyconf_checking("for __fpu_control")
+    found = (pyconf_check_func("__fpu_control", "", "HAVE___FPU_CONTROL") ? "yes" : "no")
+    pyconf_result(found)
+    if ((!((found != "") && (found != "no")))) {
+        pyconf_check_lib("ieee", "__fpu_control")
+    }
     v_export("LIBM")
     if ((V["ac_sys_system"] != "Darwin")) {
         V["LIBM"] = "-lm"
@@ -5106,12 +5112,6 @@ function u_check_math_library(    found, with_libc, with_libm) {
     } else {
         pyconf_result("default LIBC=\"" V["LIBC"] "\"")
     }
-    pyconf_checking("for __fpu_control")
-    found = (pyconf_check_func("__fpu_control", "", "HAVE___FPU_CONTROL") ? "yes" : "no")
-    pyconf_result(found)
-    if ((!((found != "") && (found != "no")))) {
-        pyconf_check_lib("ieee", "__fpu_control")
-    }
 }
 
 function u__define_float_big() {
@@ -5391,12 +5391,12 @@ function u_detect_libmpdec(    _i_p, _n_p, _opt_result, ac_cv_gcc_asm_for_x64, a
         } else if ((libmpdec_machine == "unknown")) {
             pyconf_fatal("_decimal: unsupported architecture")
         }
-        if (((V["have_ipa_pure_const_bug"] != "") && (V["have_ipa_pure_const_bug"] != "no"))) {
-            V["LIBMPDEC_CFLAGS"] = V["LIBMPDEC_CFLAGS"] " -fno-ipa-pure-const"
-        }
-        if (((V["have_glibc_memmove_bug"] != "") && (V["have_glibc_memmove_bug"] != "no"))) {
-            V["LIBMPDEC_CFLAGS"] = V["LIBMPDEC_CFLAGS"] " -U_FORTIFY_SOURCE"
-        }
+    }
+    if (((V["have_ipa_pure_const_bug"] != "") && (V["have_ipa_pure_const_bug"] != "no"))) {
+        V["LIBMPDEC_CFLAGS"] = V["LIBMPDEC_CFLAGS"] " -fno-ipa-pure-const"
+    }
+    if (((V["have_glibc_memmove_bug"] != "") && (V["have_glibc_memmove_bug"] != "no"))) {
+        V["LIBMPDEC_CFLAGS"] = V["LIBMPDEC_CFLAGS"] " -U_FORTIFY_SOURCE"
     }
     v_export("LIBMPDEC_CFLAGS")
     v_export("LIBMPDEC_LIBS")
@@ -5657,7 +5657,7 @@ function u_check_network_libs(    libs_val) {
     if (pyconf_check_lib("nsl", "t_open", "", "")) {
         V["LIBS"] = "-lnsl " V["LIBS"]
     }
-    if (pyconf_check_lib("socket", "socket", "", "")) {
+    if (pyconf_check_lib("socket", "socket", "", V["LIBS"])) {
         V["LIBS"] = "-lsocket " V["LIBS"]
     }
     if (_str_startswith(V["ac_sys_system"] "/" V["ac_sys_release"], "Haiku")) {
@@ -5857,7 +5857,7 @@ function u_check_getaddrinfo(    GETADDRINFO_TEST, ac_cv_buggy_getaddrinfo, ac_c
             if (((pyconf_cross_compiling != "") && (pyconf_cross_compiling != "no"))) {
                 if (((V["ac_sys_system"] == "Linux-android") || (V["ac_sys_system"] == "iOS"))) {
                     ac_cv_buggy_getaddrinfo = "no"
-                } else if ((V["enable_ipv6"] != "")) {
+                } else if (pyconf_option_given("enable_ipv6")) {
                     ac_cv_buggy_getaddrinfo = "no -- configured with --(en|dis)able-ipv6"
                 } else {
                     ac_cv_buggy_getaddrinfo = "yes"