fix homedir error handling for 1020+ character usernames

or 250 characters for a certain broken OS

Ref #22457
(cherry picked from commit 8c1adc8)

base/path.jl

@@ -68,7 +68,7 @@ function homedir()
         if rc == 0
             resize!(buf, sz[])
             return String(buf)
-        elseif rc == UV_ENOBUFS
+        elseif rc == Base.UV_ENOBUFS
             resize!(buf, sz[] - 1)
         else
             error("unable to retrieve home directory")

test/path.jl

@@ -197,3 +197,15 @@ test_relpath()
 # Test type stability
 @test isa(joinpath("a", "b"), String)
 @test isa(joinpath(abspath("a"), "b"), String)
+
+# homedir
+let var = is_windows() ? "USERPROFILE" : "HOME",
+    MAX_PATH = is_windows() ? 240 : 1020
+    for i = 0:9
+        local home = " "^MAX_PATH * "123456789"[1:i]
+        @test withenv(var => home) do
+            homedir()
+        end == home
+    end
+    @test isabspath(withenv(homedir, var => nothing))
+end