fix wrong definition of curl_socket_t on Windows

src/Curl/Curl.jl

@@ -26,13 +26,35 @@ export
         remove_handle
 
 using LibCURL
-using LibCURL: curl_off_t
+using LibCURL: curl_off_t, libcurl
 # not exported: https://github.com/JuliaWeb/LibCURL.jl/issues/87
 
 # constants that LibCURL should have but doesn't
 const CURLE_PEER_FAILED_VERIFICATION = 60
 const CURLSSLOPT_REVOKE_BEST_EFFORT = 1 << 3
 
+# these are incorrectly defined on Windows by LibCURL:
+if Sys.iswindows()
+    const curl_socket_t = Base.OS_HANDLE
+    const CURL_SOCKET_TIMEOUT = Base.INVALID_OS_HANDLE
+else
+    const curl_socket_t = Cint
+    const CURL_SOCKET_TIMEOUT = -1
+end
+
+# definitions affected by incorrect curl_socket_t (copied verbatim):
+function curl_multi_socket_action(multi_handle, s, ev_bitmask, running_handles)
+    ccall((:curl_multi_socket_action, libcurl), CURLMcode, (Ptr{CURLM}, curl_socket_t, Cint, Ptr{Cint}), multi_handle, s, ev_bitmask, running_handles)
+end
+function curl_multi_assign(multi_handle, sockfd, sockp)
+    ccall((:curl_multi_assign, libcurl), CURLMcode, (Ptr{CURLM}, curl_socket_t, Ptr{Cvoid}), multi_handle, sockfd, sockp)
+end
+
+# additional curl_multi_socket_action method
+function curl_multi_socket_action(multi_handle, s, ev_bitmask)
+    curl_multi_socket_action(multi_handle, s, ev_bitmask, Ref{Cint}())
+end
+
 using FileWatching
 using NetworkOptions
 using Base: OS_HANDLE, preserve_handle, unpreserve_handle

src/Curl/utils.jl

@@ -31,12 +31,6 @@ macro check(ex::Expr)
     end
 end
 
-# additional libcurl methods
-
-function curl_multi_socket_action(multi_handle, s, ev_bitmask)
-    LibCURL.curl_multi_socket_action(multi_handle, s, ev_bitmask, Ref{Cint}())
-end
-
 # curl string list structure
 
 struct curl_slist_t