Subject: bug#55764: 29.0.50; sh-mode: Support mksh's alternate case brace syntax

From: Stefan Monnier <[email-masked]>
Date: Sat, 30 Sep 2023 23:37:28 -0400

> To no one's surprise, the patch is not the right approach.  IIUC, when I
> use braces, *pattern) thingies are not recognised as "case-)" anymore so
> sh-indent-for-case-label does not get applied.  I tried a bit more but I
> only got it to respect the first line but still it is definitely not the
> right approach,

The first part of the puzzle is to fix the syntax-category of the `)` so
it's recognized as a "case-)" rather than a normal ("matched") paren.

The patch below seems to do the trick.

        Stefan

diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index cc521cb0591..b34be83367a 100644
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -1053,7 +1053,8 @@ sh-font-lock-paren
                     ;; a normal command rather than the real `in' keyword.
                     ;; I.e. we should look back to try and find the
                     ;; corresponding `case'.
-                    (and (looking-at ";\\(?:;&?\\|[&|]\\)\\|\\_<in")
+                    ;; Also recognize OpenBSD's case X { ... } (bug#55764).
+                    (and (looking-at ";\\(?:;&?\\|[&|]\\)\\|\\_<in\\|.{")
                          ;; ";; esac )" is a case that looks
                          ;; like a case-pattern but it's really just a close
                          ;; paren after a case statement.  I.e. if we skipped
@@ -2053,9 +2054,9 @@ sh-smie-sh-rules
                              (sh-var-value 'sh-indent-for-case-label)))
     (`(:before . ,(or "(" "{" "[" "while" "if" "for" "case"))
      (cond
-      ((and (equal token "{") (smie-rule-parent-p "for"))
+      ((and (equal token "{") (smie-rule-parent-p "for" "case"))
        (let ((data (smie-backward-sexp "in")))
-         (when (equal (nth 2 data) "for")
+         (when (member (nth 2 data) '("for" "case"))
            `(column . ,(smie-indent-virtual)))))
       ((not (smie-rule-prev-p "&&" "||" "|"))
        (when (smie-rule-hanging-p)
diff --git a/test/manual/indent/shell.sh b/test/manual/indent/shell.sh
index 5b3fb0e66fb..42a981d312e 100755
--- a/test/manual/indent/shell.sh
+++ b/test/manual/indent/shell.sh
@@ -189,3 +189,10 @@ bar ()
 
     fi
 }
+
+case $i {                       # Bug#55764
+    *pattern)
+        (cd .; echo hi);
+        do1 ;;
+    *pattern2) do2 ;;
+}