Prompt for private if SSH_KEY_PATH unset

Allows the user to confirm they want to use the default private key.
During development it was noticed that the username was only being
filled in if prompting was allowed.

base/libgit2/callbacks.jl

@@ -82,6 +82,10 @@ function authenticate_ssh(libgit2credptr::Ptr{Ptr{Void}}, p::CredentialPayload,
     end
 
     if p.use_env && (!revised || !isfilled(cred))
+        if isempty(cred.user) && username_ptr != Cstring(C_NULL)
+            cred.user = unsafe_string(username_ptr)
+        end
+
         cred.prvkey = Base.get(ENV, "SSH_KEY_PATH") do
             default = joinpath(homedir(), ".ssh", "id_rsa")
             if isempty(cred.prvkey) && isfile(default)
@@ -107,22 +111,18 @@ function authenticate_ssh(libgit2credptr::Ptr{Ptr{Void}}, p::CredentialPayload,
     end
 
     if p.remaining_prompts > 0 && (!revised || !isfilled(cred))
-        # if username is not provided or empty, then prompt for it
-        username = username_ptr != Cstring(C_NULL) ? unsafe_string(username_ptr) : ""
-        if isempty(username)
+        if isempty(cred.user) || username_ptr == Cstring(C_NULL)
             url = git_url(scheme=p.scheme, host=p.host)
             response = Base.prompt("Username for '$url'", default=cred.user)
             isnull(response) && return user_abort()
             cred.user = unsafe_get(response)
-        else
-            cred.user = username
         end
 
         url = git_url(scheme=p.scheme, host=p.host, username=cred.user)
 
         # For SSH we need a private key location
         last_private_key = cred.prvkey
-        if !isfile(cred.prvkey) || !revised
+        if !isfile(cred.prvkey) || !revised || !haskey(ENV, "SSH_KEY_PATH")
             response = Base.prompt("Private key location for '$url'", default=cred.prvkey)
             isnull(response) && return user_abort()
             cred.prvkey = expanduser(unsafe_get(response))

test/libgit2.jl

@@ -2025,27 +2025,54 @@ mktempdir() do dir
                 url = "github.com:test/package.jl"
 
                 default_key = joinpath(home_dir, ".ssh", "id_rsa")
-                default_cred = LibGit2.SSHCredentials("git", "", default_key, default_key * ".pub")
-
-                # Copy the stored private/public
-                key = joinpath(KEY_DIR, "valid")
                 mkdir(dirname(default_key))
-                cp(key, default_key)
-                cp(key * ".pub", default_key * ".pub")
 
-                ssh_ex = quote
-                    include($LIBGIT2_HELPER_PATH)
-                    credential_loop($default_cred, $url, "git")
+                valid_key = joinpath(KEY_DIR, "valid")
+                valid_cred = LibGit2.SSHCredentials("git", "", valid_key, valid_key * ".pub")
+
+                valid_p_key = joinpath(KEY_DIR, "valid-passphrase")
+                passphrase = "secret"
+                valid_p_cred = LibGit2.SSHCredentials("git", passphrase, valid_p_key, valid_p_key * ".pub")
+
+                function gen_ex(cred)
+                    quote
+                        valid_cred = $cred
+
+                        default_cred = deepcopy(valid_cred)
+                        default_cred.prvkey = $default_key
+                        default_cred.pubkey = $default_key * ".pub"
+
+                        cp(valid_cred.prvkey, default_cred.prvkey)
+                        cp(valid_cred.pubkey, default_cred.pubkey)
+
+                        try
+                            include($LIBGIT2_HELPER_PATH)
+                            credential_loop(default_cred, $url, "git")
+                        finally
+                            rm(default_cred.prvkey)
+                            rm(default_cred.pubkey)
+                        end
+                    end
                 end
 
                 withenv("SSH_KEY_PATH" => nothing,
                         "SSH_PUB_KEY_PATH" => nothing,
                         "SSH_KEY_PASS" => nothing,
                         HOME => home_dir) do
 
-                    @test isfile(joinpath(homedir(), ".ssh", "id_rsa"))
+                    # Automatically use the default key
+                    ex = gen_ex(valid_cred)
+                    err, auth_attempts = challenge_prompt(ex, [])
+                    @test err == git_ok
+                    @test auth_attempts == 1
 
-                    err, auth_attempts = challenge_prompt(ssh_ex, [])
+                    # Confirm the private key if any other prompting is required
+                    ex = gen_ex(valid_p_cred)
+                    challenges = [
+                        "Private key location for '[email protected]' [$default_key]:" => "\n",
+                        "Passphrase for $default_key:" => "$passphrase\n",
+                    ]
+                    err, auth_attempts = challenge_prompt(ex, challenges)
                     @test err == git_ok
                     @test auth_attempts == 1
                 end