Macro hygiene.

Most of these changes are just paranoia (or "belt and braces" if you
want to be more charitable) but it makes sense to be a bit careful.

src/clj_libssh2/error.clj

@@ -167,8 +167,9 @@
    (but not equal to LIBSSH2_ERROR_EAGAIN). In those cases an exception will be
    thrown using maybe-throw-error."
   [session & body]
-  `(let [res# (do ~@body)]
-     (maybe-throw-error (:session ~session) res#)
+  `(let [session# ~session
+         res# (do ~@body)]
+     (maybe-throw-error (:session session#) res#)
      res#))
 
 (defn get-timeout

src/clj_libssh2/session.clj

@@ -166,10 +166,11 @@
                   default-opts) plus :hostname, :port and :credentials which
                   will be passed as the first three arguments to open."
   [session session-params & body]
-  `(let [~session (open (:hostname ~session-params)
-                        (:port ~session-params)
-                        (:credentials ~session-params)
-                        (dissoc ~session-params :hostname :port :credentials))]
+  `(let [session-params# ~session-params
+         ~session (open (:hostname session-params#)
+                        (:port session-params#)
+                        (:credentials session-params#)
+                        (dissoc session-params# :hostname :port :credentials))]
      (try
        (do ~@body)
        (finally

src/clj_libssh2/socket.clj

@@ -98,20 +98,22 @@
 (defmacro block
   "Turn a non-blocking call that returns EAGAIN into a blocking one."
   [session & body]
-  `(let [start-time# (System/currentTimeMillis)]
+  `(let [session# ~session
+         start-time# (System/currentTimeMillis)]
      (while (= libssh2/ERROR_EAGAIN (do ~@body))
-       (handle-errors ~session
-         (wait ~session start-time#)))))
+       (handle-errors session#
+         (wait session# start-time#)))))
 
 (defmacro block-return
   "Similar to block, but for functions that return a pointer"
   [session & body]
-  `(let [start-time# (System/currentTimeMillis)]
+  `(let [session# ~session
+         start-time# (System/currentTimeMillis)]
      (loop [result# (do ~@body)]
        (if (nil? result#)
-         (let [errno# (libssh2-session/last-errno (:session ~session))]
-           (handle-errors ~session errno#)
+         (let [errno# (libssh2-session/last-errno (:session session#))]
+           (handle-errors session# errno#)
            (when (= libssh2/ERROR_EAGAIN errno#)
-             (wait ~session start-time#))
+             (wait session# start-time#))
            (recur (do ~@body)))
          result#))))

src/clj_libssh2/ssh.clj

@@ -25,14 +25,15 @@
                     describing a potential session (in which case this calls
                     clj-libssh2.session/with-session to create the session)."
   [session session-or-host & body]
-  `(if (instance? Session ~session-or-host)
-     (let [~session ~session-or-host]
-       (do ~@body))
-     (let [defaults# {:hostname "127.0.0.1"
-                      :port 22
-                      :credentials {:username (System/getProperty "user.name")}}]
-       (session/with-session ~session (merge defaults# ~session-or-host)
-         (do ~@body)))))
+  `(let [session-or-host# ~session-or-host]
+     (if (instance? Session session-or-host#)
+       (let [~session session-or-host#]
+         (do ~@body))
+       (let [defaults# {:hostname "127.0.0.1"
+                        :port 22
+                        :credentials {:username (System/getProperty "user.name")}}]
+         (session/with-session ~session (merge defaults# session-or-host#)
+           (do ~@body))))))
 
 (defn exec
   "Execute a command and get the results.