From ffab420e4318c65387a72a8572f2e40e301d0028 Mon Sep 17 00:00:00 2001
From: Fabian Homborg <FHomborg@gmail.com>
Date: Wed, 12 Dec 2018 15:12:12 +0100
Subject: [PATCH] Add fallback wcstod_l for musl

Just sets locale to "C" (because that's the only one we need), does
wcstod and resets the locale.

No idea why uselocale(loc) failed for me, but it did.

Fixes #5407.
---
 cmake/ConfigureChecks.cmake |  1 +
 configure.ac                |  1 +
 src/fallback.cpp            | 15 +++++++++++++++
 src/fallback.h              |  4 ++++
 4 files changed, 21 insertions(+)

diff --git a/cmake/ConfigureChecks.cmake b/cmake/ConfigureChecks.cmake
index 052a39172..1444361e9 100644
--- a/cmake/ConfigureChecks.cmake
+++ b/cmake/ConfigureChecks.cmake
@@ -72,6 +72,7 @@ CHECK_CXX_SYMBOL_EXISTS(wcsdup wchar.h HAVE_WCSDUP)
 CHECK_CXX_SYMBOL_EXISTS(wcslcpy wchar.h HAVE_WCSLCPY)
 CHECK_CXX_SYMBOL_EXISTS(wcsncasecmp wchar.h HAVE_WCSNCASECMP)
 CHECK_CXX_SYMBOL_EXISTS(wcsndup wchar.h HAVE_WCSNDUP)
+CHECK_CXX_SYMBOL_EXISTS(wcstod_l wchar.h HAVE_WCSTOD_L)
 
 CHECK_CXX_SYMBOL_EXISTS(_sys_errs stdlib.h HAVE__SYS__ERRS)
 
diff --git a/configure.ac b/configure.ac
index ebaceb1de..7070799ff 100644
--- a/configure.ac
+++ b/configure.ac
@@ -316,6 +316,7 @@ AC_STRUCT_DIRENT_D_TYPE
 #
 
 AC_CHECK_FUNCS( wcsndup )
+AC_CHECK_FUNCS( wcstod_l )
 AC_CHECK_FUNCS( futimes )
 AC_CHECK_FUNCS( wcslcpy lrand48_r killpg )
 AC_CHECK_FUNCS( backtrace_symbols getifaddrs )
diff --git a/src/fallback.cpp b/src/fallback.cpp
index 42a9d62d2..d7e4e508e 100644
--- a/src/fallback.cpp
+++ b/src/fallback.cpp
@@ -388,3 +388,18 @@ int flock(int fd, int op) {
 }
 
 #endif  // HAVE_FLOCK
+
+#ifndef HAVE_WCSTOD_L
+// musl doesn't feature wcstod_l,
+// so we just wrap wcstod.
+double wcstod_l(const wchar_t *enptr, wchar_t **endptr, locale_t loc) {
+    char *saved_locale = strdup(setlocale(LC_NUMERIC, NULL));
+    // Yes, this is hardcoded to use the "C" locale.
+    // That's the only thing we need, and uselocale(loc) broke in my testing.
+    setlocale(LC_NUMERIC, "C");
+    double ret = wcstod(enptr, endptr);
+    setlocale(LC_NUMERIC, saved_locale);
+    free(saved_locale);
+    return ret;
+}
+#endif // defined(wcstod_l)
diff --git a/src/fallback.h b/src/fallback.h
index 44ddee398..b0680de05 100644
--- a/src/fallback.h
+++ b/src/fallback.h
@@ -198,3 +198,7 @@ int flock(int fd, int op);
 #endif
 
 #endif
+
+#ifndef wcstod_l
+double wcstod_l(const wchar_t *enptr, wchar_t **endptr, locale_t loc);
+#endif