Add the ssh_key_from_memory optional feature. (#331)

* Add the ssh_key_from_memory optional feature.

* Enable the ssh_key_from_memory feature by default.

Users with older versions of libssh can still disable it if needed.

Cargo.toml

@@ -41,10 +41,11 @@ thread-id = "3.3.0" # remove when we work with minimal-versions without it
 
 [features]
 unstable = []
-default = ["ssh", "https", "curl"]
+default = ["ssh", "https", "curl", "ssh_key_from_memory"]
 ssh = ["libgit2-sys/ssh"]
 https = ["libgit2-sys/https", "openssl-sys", "openssl-probe"]
 curl = ["libgit2-sys/curl"]
+ssh_key_from_memory = ["libgit2-sys/ssh_key_from_memory"]
 
 [workspace]
 members = ["systest", "git2-curl"]

libgit2-sys/Cargo.toml

@@ -33,3 +33,4 @@ openssl-sys = { version = "0.9", optional = true }
 ssh = ["libssh2-sys"]
 https = ["openssl-sys"]
 curl = ["curl-sys"]
+ssh_key_from_memory = []

libgit2-sys/build.rs

@@ -48,6 +48,9 @@ fn main() {
     let msvc = target.contains("msvc");
     let mut cfg = cmake::Config::new("libgit2");
 
+    #[cfg(feature = "ssh_key_from_memory")] 
+    cfg.define("GIT_SSH_MEMORY_CREDENTIALS", "1");
+
     if msvc {
         // libgit2 passes the /GL flag to enable whole program optimization, but
         // this requires that the /LTCG flag is passed to the linker later on,