From b06d43884d7f924162ac5698d3b215f4004395e7 Mon Sep 17 00:00:00 2001
From: Kodi Arfer <git@arfer.net>
Date: Tue, 7 Jan 2025 13:13:21 -0500
Subject: [PATCH] Fix the handling of dot expressions with ""

---
 NEWS.rst                   | 4 ++++
 hy/macros.py               | 6 +++++-
 tests/native_tests/dots.hy | 8 ++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/NEWS.rst b/NEWS.rst
index e82b571da..603eea0ed 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -9,6 +9,10 @@ New Features
 ------------------------------
 * New pragma `hy`.
 
+Bug Fixes
+------------------------------
+* Fixed a crash from using an empty string in a `(. …)` expression.
+
 1.0.0 ("Afternoon Review", released 2024-09-22)
 ======================================================================
 
diff --git a/hy/macros.py b/hy/macros.py
index ef591523c..afc764e25 100644
--- a/hy/macros.py
+++ b/hy/macros.py
@@ -357,7 +357,11 @@ def macroexpand(tree, module, compiler=None, once=False, result_ok=True):
     while isinstance(tree, Expression) and tree:
 
         fn = tree[0]
-        if isinstance(fn, Expression) and fn and fn[0] == Symbol("."):
+        if (
+                isinstance(fn, Expression) and
+                fn and
+                fn[0] == Symbol(".") and
+                all(isinstance(x, Symbol) for x in fn)):
             fn = ".".join(map(mangle, fn[1:]))
         elif isinstance(fn, Symbol):
             fn = mangle(fn)
diff --git a/tests/native_tests/dots.hy b/tests/native_tests/dots.hy
index ef3ae3c66..76a047ad2 100644
--- a/tests/native_tests/dots.hy
+++ b/tests/native_tests/dots.hy
@@ -35,6 +35,14 @@
   (assert (= (.__str__ :foo) ":foo")))
 
 
+(defn test-dot-empty-string []
+  ; https://github.com/hylang/hy/issues/2625
+  (assert (=
+    ((. "" join) ["aa" "bb" "cc"])
+    (.join "" ["aa" "bb" "cc"])
+    "aabbcc")))
+
+
 (defn test-dot-macro []
   (defclass mycls [object])