From b7fe3190bba1e7d314d3b4e65000f9cd8b6d6e38 Mon Sep 17 00:00:00 2001
From: Johannes Altmanninger <aclopte@gmail.com>
Date: Wed, 8 Oct 2025 10:30:35 +0200
Subject: [PATCH] Revert "builtin function: remove dead code"

This reverts commit 993b977c9b1d730c66c132b875e7e0db122e881d.

Fixes #11912
---
 CHANGELOG.rst              |  7 +++++++
 po/de.po                   |  4 ++++
 po/en.po                   |  4 ++++
 po/fr.po                   |  4 ++++
 po/pl.po                   |  4 ++++
 po/pt_BR.po                |  4 ++++
 po/sv.po                   |  4 ++++
 po/zh_CN.po                |  4 ++++
 src/builtins/function.rs   | 18 +++++++++++++++---
 tests/checks/function.fish |  6 ++++++
 10 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index f16d75c5b..dbbc1797c 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,13 @@
 fish ?.?.? (released ???)
 =========================
 
+fish 4.1.3 (released ???)
+=========================
+
+This release fixes the following regressions identified in 4.1.0:
+
+- Crash on invalid :doc:`function <cmds/function>` call (:issue:`11912`).
+
 fish 4.1.2 (released October 7, 2025)
 =====================================
 
diff --git a/po/de.po b/po/de.po
index c19042ba2..7de05fed7 100644
--- a/po/de.po
+++ b/po/de.po
@@ -82,6 +82,10 @@ msgstr "$status ist kein gültiger Befehl. Siehe `help conditions`"
 msgid "%.*s: invalid conversion specification"
 msgstr "%.*s: Ungültige Umwandlungsspezifikation"
 
+#, c-format
+msgid "%ls: function name required"
+msgstr "%ls: Brauche Funktionsnamen"
+
 #, c-format
 msgid "%s"
 msgstr ""
diff --git a/po/en.po b/po/en.po
index 0013087c5..4a4ef7657 100644
--- a/po/en.po
+++ b/po/en.po
@@ -80,6 +80,10 @@ msgstr ""
 msgid "%.*s: invalid conversion specification"
 msgstr "%.*s: invalid conversion specification"
 
+#, c-format
+msgid "%ls: function name required"
+msgstr ""
+
 #, c-format
 msgid "%s"
 msgstr ""
diff --git a/po/fr.po b/po/fr.po
index 115cf6f3d..a115ffd20 100644
--- a/po/fr.po
+++ b/po/fr.po
@@ -181,6 +181,10 @@ msgstr ""
 msgid "%.*s: invalid conversion specification"
 msgstr "%.*s : spécification de conversion invalide"
 
+#, c-format
+msgid "%ls: function name required"
+msgstr ""
+
 #, c-format
 msgid "%s"
 msgstr ""
diff --git a/po/pl.po b/po/pl.po
index 98a01916c..58c27e430 100644
--- a/po/pl.po
+++ b/po/pl.po
@@ -76,6 +76,10 @@ msgstr ""
 msgid "%.*s: invalid conversion specification"
 msgstr ""
 
+#, c-format
+msgid "%ls: function name required"
+msgstr ""
+
 #, c-format
 msgid "%s"
 msgstr ""
diff --git a/po/pt_BR.po b/po/pt_BR.po
index af7b91020..93e7f3f9e 100644
--- a/po/pt_BR.po
+++ b/po/pt_BR.po
@@ -81,6 +81,10 @@ msgstr ""
 msgid "%.*s: invalid conversion specification"
 msgstr "%.*s: especificação de conversão inválida"
 
+#, c-format
+msgid "%ls: function name required"
+msgstr ""
+
 #, c-format
 msgid "%s"
 msgstr ""
diff --git a/po/sv.po b/po/sv.po
index d2895e808..fb2bed6da 100644
--- a/po/sv.po
+++ b/po/sv.po
@@ -77,6 +77,10 @@ msgstr ""
 msgid "%.*s: invalid conversion specification"
 msgstr ""
 
+#, c-format
+msgid "%ls: function name required"
+msgstr ""
+
 #, c-format
 msgid "%s"
 msgstr ""
diff --git a/po/zh_CN.po b/po/zh_CN.po
index 6b6cff0c3..a5e6ecd78 100644
--- a/po/zh_CN.po
+++ b/po/zh_CN.po
@@ -103,6 +103,10 @@ msgstr "$status 不是有效的命令。参见 `help conditions`"
 msgid "%.*s: invalid conversion specification"
 msgstr "%.*s: 无效的转换规范"
 
+#, c-format
+msgid "%ls: function name required"
+msgstr "%ls: 函数名称是必须的"
+
 #, c-format
 msgid "%s"
 msgstr "%s"
diff --git a/src/builtins/function.rs b/src/builtins/function.rs
index fa3089e59..88649cfb6 100644
--- a/src/builtins/function.rs
+++ b/src/builtins/function.rs
@@ -243,7 +243,19 @@ fn parse_cmd_opts(
     STATUS_CMD_OK
 }
 
-fn validate_function_name(function_name: &wstr, cmd: &wstr, streams: &mut IoStreams) -> c_int {
+fn validate_function_name(
+    argv: &mut [&wstr],
+    function_name: &mut WString,
+    cmd: &wstr,
+    streams: &mut IoStreams,
+) -> c_int {
+    if argv.len() < 2 {
+        streams
+            .err
+            .append(wgettext_fmt!("%ls: function name required", cmd));
+        return STATUS_INVALID_ARGS;
+    }
+    *function_name = argv[1].to_owned();
     if !valid_func_name(function_name) {
         streams.err.append(wgettext_fmt!(
             "%s: %s: invalid function name",
@@ -281,8 +293,8 @@ pub fn function(
     let cmd = argv[0];
 
     // A valid function name has to be the first argument.
-    let function_name = argv[1].to_owned();
-    let mut retval = validate_function_name(&function_name, cmd, streams);
+    let mut function_name = WString::new();
+    let mut retval = validate_function_name(argv, &mut function_name, cmd, streams);
     if retval != STATUS_CMD_OK {
         return retval;
     }
diff --git a/tests/checks/function.fish b/tests/checks/function.fish
index 2e30e08c7..dafbc6c1e 100644
--- a/tests/checks/function.fish
+++ b/tests/checks/function.fish
@@ -186,4 +186,10 @@ function foo; echo before; end
 foo (functions --erase foo)
 # CHECKERR: error: Unknown function 'foo'
 
+function ()
+end
+# CHECKERR: {{.*}}/tests/checks/function.fish (line {{\d+}}): function: function name required
+# CHECKERR: function ()
+# CHECKERR: ^
+
 exit 0