From 9fa52ad39c65486b982325ac7a1bc3c6ab672757 Mon Sep 17 00:00:00 2001
From: Stefan Karpinski <stefan@karpinski.org>
Date: Fri, 13 Jul 2018 15:34:02 -0400
Subject: [PATCH] lazy LibGit2 initialization

---
 base/precompile.jl            | 2 +-
 stdlib/LibGit2/src/LibGit2.jl | 8 ++++----
 stdlib/LibGit2/src/error.jl   | 1 +
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/base/precompile.jl b/base/precompile.jl
index 16f58b58ff85b..0ec63328ef4b8 100644
--- a/base/precompile.jl
+++ b/base/precompile.jl
@@ -465,7 +465,7 @@ precompile(Tuple{typeof(Core.Compiler.length), Tuple{typeof(Base.:(*)), Int64}})
 precompile(Tuple{typeof(Core.Compiler.length), Tuple{typeof(Base.open_flags)}})
 precompile(Tuple{typeof(Core.Compiler.vect), Type{typeof(typeassert)}})
 precompile(Tuple{typeof(Distributed.terminate_all_workers)})
-precompile(Tuple{typeof(LibGit2.__init__)})
+precompile(Tuple{typeof(LibGit2.initialize)})
 precompile(Tuple{typeof(Logging.__init__)})
 precompile(Tuple{typeof(Logging.default_metafmt), Base.CoreLogging.LogLevel, Module, Symbol, Symbol, String, Int64})
 precompile(Tuple{typeof(Logging.default_metafmt), Base.CoreLogging.LogLevel, Nothing, Symbol, Symbol, String, Int64})
diff --git a/stdlib/LibGit2/src/LibGit2.jl b/stdlib/LibGit2/src/LibGit2.jl
index 55dde9a5a8203..08e35611376bc 100644
--- a/stdlib/LibGit2/src/LibGit2.jl
+++ b/stdlib/LibGit2/src/LibGit2.jl
@@ -16,7 +16,7 @@ export with, GitRepo, GitConfig
 const GITHUB_REGEX =
     r"^(?:git@|git://|https://(?:[\w\.\+\-]+@)?)github.com[:/](([^/].+)/(.+?))(?:\.git)?$"i
 
-const REFCOUNT = Threads.Atomic{UInt}()
+const REFCOUNT = Threads.Atomic{UInt}(0)
 
 include("utils.jl")
 include("consts.jl")
@@ -972,12 +972,12 @@ function set_ssl_cert_locations(cert_loc)
           Cint(Consts.SET_SSL_CERT_LOCATIONS), cert_file, cert_dir)
 end
 
-function __init__()
-    @check ccall((:git_libgit2_init, :libgit2), Cint, ())
+function initialize()
     REFCOUNT[] = 1
+    @check ccall((:git_libgit2_init, :libgit2), Cint, ())
 
     atexit() do
-        if Threads.atomic_sub!(REFCOUNT, UInt(1)) == 1
+        if Threads.atomic_sub!(REFCOUNT, UInt(1)) >= 1
             # refcount zero, no objects to be finalized
             ccall((:git_libgit2_shutdown, :libgit2), Cint, ())
         end
diff --git a/stdlib/LibGit2/src/error.jl b/stdlib/LibGit2/src/error.jl
index b64e9f1b8d923..93e157fd14e2f 100644
--- a/stdlib/LibGit2/src/error.jl
+++ b/stdlib/LibGit2/src/error.jl
@@ -93,6 +93,7 @@ end # Error module
 
 macro check(git_func)
     quote
+        REFCOUNT[] == 0 && initialize()
         err = Cint($(esc(git_func::Expr)))
         if err < 0
             throw(Error.GitError(err))