diff --git a/CONTRIBUTE b/CONTRIBUTE
index eda300f01bc..be10dbda8b3 100644
--- a/CONTRIBUTE
+++ b/CONTRIBUTE
@@ -234,7 +234,9 @@ formatting them:
 - Lines in ChangeLog entries should preferably be not longer than 63
   characters, and must not exceed 78 characters, unless they consist
   of a single word of at most 140 characters; this 78/140 limit is
-  enforced by a commit hook.
+  enforced by a commit hook.  (The 63-character preference is to
+  avoid too-long lines in the ChangeLog file generated from Git logs,
+  where each entry line is indented by a TAB.)
 
 - If only a single file is changed, the summary line can be the normal
   first line of a ChangeLog entry (starting with the asterisk).  Then
diff --git a/lisp/progmodes/typescript-ts-mode.el b/lisp/progmodes/typescript-ts-mode.el
index 24953f629de..6f807c254bd 100644
--- a/lisp/progmodes/typescript-ts-mode.el
+++ b/lisp/progmodes/typescript-ts-mode.el
@@ -155,7 +155,7 @@ Argument LANGUAGE is either `typescript' or `tsx'."
   (typescript-ts-mode--check-dialect language)
   `((,language
      ((parent-is "program") column-0 0)
-     ((node-is "}") parent-bol 0)
+     ((node-is "}") standalone-parent 0)
      ((node-is ")") parent-bol 0)
      ((node-is "]") parent-bol 0)
      ((node-is ">") parent-bol 0)
@@ -165,7 +165,7 @@ Argument LANGUAGE is either `typescript' or `tsx'."
      ((parent-is "ternary_expression") standalone-parent typescript-ts-mode-indent-offset)
      ((parent-is "member_expression") parent-bol typescript-ts-mode-indent-offset)
      ((parent-is "named_imports") parent-bol typescript-ts-mode-indent-offset)
-     ((parent-is "statement_block") parent-bol typescript-ts-mode-indent-offset)
+     ((parent-is "statement_block") standalone-parent typescript-ts-mode-indent-offset)
      ((or (node-is "case")
           (node-is "default"))
       parent-bol typescript-ts-mode-indent-offset)
diff --git a/test/lisp/progmodes/typescript-ts-mode-resources/indent.erts b/test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
index e8b1d57f132..210bfcabd41 100644
--- a/test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
+++ b/test/lisp/progmodes/typescript-ts-mode-resources/indent.erts
@@ -182,3 +182,28 @@ interface Foo {
   bar?: boolean;
 }
 =-=-=
+
+Code:
+  (lambda ()
+    (setq tsx-ts-mode-indent-offset 2)
+    (tsx-ts-mode)
+    (setq indent-tabs-mode nil)
+    (indent-region (line-beginning-position 7) (point-max)))
+
+Name: Function body with params misindented (bug#78121)
+
+=-=
+const f1 = (a1: string,
+            a2: number) => {
+    const f2 = (a1: string,
+                a2: number) => {
+      const f3 = (a1: string,
+                  a2: number) =>
+        {
+          return;
+        }
+      return;
+    }
+  return;
+}
+=-=-=