From 684e62e9039d4c8b1a80edc219519d353d64adbb Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Thu, 12 Mar 2020 00:50:45 +1300
Subject: [PATCH] Fix Rust static library linking for Windows builds

The library renaming step is necessary because the naming convention
used by rustc does not match the naming convention for libtool/MinGW.
---
 configure.ac    |  1 +
 src/Makefile.am | 16 ++++++++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/configure.ac b/configure.ac
index 9958a3783..66bb96316 100644
--- a/configure.ac
+++ b/configure.ac
@@ -821,6 +821,7 @@ fi
 RUST_LIBS=""
 case $host in
   *mingw*)
+    RUST_LIBS="$RUST_LIBS -luserenv"
     ;;
   *)
     RUST_LIBS="$RUST_LIBS -ldl"
diff --git a/src/Makefile.am b/src/Makefile.am
index 81acc739e..8dfd66524 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -38,11 +38,7 @@ LIBBITCOIN_COMMON=libbitcoin_common.a
 LIBBITCOIN_CLI=libbitcoin_cli.a
 LIBBITCOIN_UTIL=libbitcoin_util.a
 LIBBITCOIN_CRYPTO=crypto/libbitcoin_crypto.a
-if TARGET_WINDOWS
-LIBRUSTZCASH=$(top_builddir)/target/$(RUST_TARGET)/release/rustzcash.lib
-else
 LIBRUSTZCASH=$(top_builddir)/target/$(RUST_TARGET)/release/librustzcash.a
-endif
 LIBSECP256K1=secp256k1/libsecp256k1.la
 LIBUNIVALUE=univalue/libunivalue.la
 LIBZCASH=libzcash.a
@@ -85,7 +81,19 @@ endif
 cargo-build: $(CARGO_CONFIGURED)
 	$(RUST_ENV_VARS) $(CARGO) build $(RUST_BUILD_OPTS) --manifest-path $(top_srcdir)/Cargo.toml
 
+if TARGET_WINDOWS
+LIBRUSTZCASH_WIN=$(top_builddir)/target/$(RUST_TARGET)/release/rustzcash.lib
+
+$(LIBRUSTZCASH_WIN): cargo-build
+
+# This ensures that the Rust library is correctly linked in by libtool.
+# See https://github.com/rust-lang/rust/issues/69904 for the underlying cause.
+$(LIBRUSTZCASH): $(LIBRUSTZCASH_WIN)
+	$(AM_V_at)cp $< $@
+
+else
 $(LIBRUSTZCASH): cargo-build
+endif
 
 $(LIBSECP256K1): $(wildcard secp256k1/src/*) $(wildcard secp256k1/include/*)
 	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) -C $(@D) $(@F)