From 6ae16c65c73f2b61303124652c16cc2d3ce256f6 Mon Sep 17 00:00:00 2001
From: Umberto Puddu <125773480+upuddu@users.noreply.github.com>
Date: Tue, 7 Jul 2026 12:17:28 -0500
Subject: [PATCH] fix: expand format placeholder followed by a literal '}'

A placeholder immediately followed by a literal '}' (e.g. '{}}' or '{.}}')
was treated as fixed text instead of being expanded. The parser detected the
placeholder pattern but, when the next character was '}', fell through to a
branch that copied the whole sequence verbatim and dropped the trailing '}'.

Remove that branch so the placeholder is always emitted and the following '}'
is handled as ordinary literal text. This affects both --format and --exec,
which share the template parser.
---
 CHANGELOG.md    |  1 +
 src/exec/mod.rs |  7 +++----
 src/fmt/mod.rs  | 39 +++++++++++++++++++++++++++++++--------
 tests/tests.rs  |  7 +++++++
 4 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 52b09d9f3..6e6895937 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@
 - Fire the "search pattern contains a path separator" diagnostic for any pattern containing `/`, not just patterns that happen to name an existing directory. Preserves the legacy Windows behaviour that also flags native `\` separators when the pattern resolves to a real directory. See #1873.
 - Also fire the "search pattern contains a path separator" diagnostic for `--and` patterns, not only the primary positional pattern. `--and` patterns are matched against the file name just like the primary pattern, so a path separator in them silently returned zero results. See #1873.
 - Fix bug where passing "-" as a directory argument didn't actually search that directory, see #849 (@Sean-Kenneth-Doherty).
+- Fix `--format`/`--exec` placeholders that are immediately followed by a literal `}` (e.g. `{}}` or `{.}}`). The placeholder is now expanded with the `}` kept as trailing literal text, instead of the whole sequence being treated as fixed text.
 
 # 10.4.2
 
diff --git a/src/exec/mod.rs b/src/exec/mod.rs
index 03860e864..126256c2b 100644
--- a/src/exec/mod.rs
+++ b/src/exec/mod.rs
@@ -369,10 +369,9 @@ mod tests {
     fn tokens_with_literal_braces() {
         let template =
             CommandTemplate::new(vec!["{{}}", "{{", "{.}}"], ExecutionMode::OneByOne).unwrap();
-        assert_eq!(
-            generate_str(&template, "foo"),
-            vec!["{}", "{", "{.}", "foo"]
-        );
+        // `{{}}` and `{{` are literal-brace escapes, while `{.}}` expands the
+        // `{.}` placeholder and keeps the trailing `}` as a literal.
+        assert_eq!(generate_str(&template, "foo"), vec!["{}", "{", "foo}"]);
     }
 
     #[test]
diff --git a/src/fmt/mod.rs b/src/fmt/mod.rs
index 87ee41923..2eb6e9a9d 100644
--- a/src/fmt/mod.rs
+++ b/src/fmt/mod.rs
@@ -73,7 +73,12 @@ impl FormatTemplate {
                     buf += &remaining[..m.start() + BRACE_LEN];
                     remaining = &remaining[m.end()..];
                 }
-                id if !remaining[m.end()..].starts_with('}') => {
+                id => {
+                    // We found a placeholder. Add any preceding text to the
+                    // buffer, flush it, then push the placeholder token. A
+                    // literal '}' following the placeholder (as in `{}}`) is
+                    // left in `remaining` and handled as ordinary text on the
+                    // next iteration.
                     buf += &remaining[..m.start()];
                     if !buf.is_empty() {
                         tokens.push(Token::Text(std::mem::take(&mut buf)));
@@ -81,13 +86,6 @@ impl FormatTemplate {
                     tokens.push(token_from_pattern_id(id));
                     remaining = &remaining[m.end()..];
                 }
-                _ => {
-                    // We got a normal pattern, but the final "}"
-                    // is escaped, so add up to that to the buffer, then
-                    // skip the final }
-                    buf += &remaining[..m.end()];
-                    remaining = &remaining[m.end() + BRACE_LEN..];
-                }
             }
         }
         // Add the rest of the string to the buffer, and add the final buffer to the tokens
@@ -233,6 +231,31 @@ mod fmt_tests {
         );
     }
 
+    #[test]
+    fn parse_placeholder_followed_by_literal_brace() {
+        use Token::*;
+
+        // A placeholder immediately followed by a literal '}' should still be
+        // expanded, with the '}' kept as trailing literal text.
+        assert_eq!(
+            FormatTemplate::parse("{}}"),
+            FormatTemplate::Tokens(vec![Placeholder, Text("}".into())])
+        );
+        assert_eq!(
+            FormatTemplate::parse("{/}}"),
+            FormatTemplate::Tokens(vec![Basename, Text("}".into())])
+        );
+
+        let mut path = PathBuf::new();
+        path.push("a");
+        path.push("file.txt");
+        let expanded = FormatTemplate::parse("{}}")
+            .generate(&path, Some("/"))
+            .into_string()
+            .unwrap();
+        assert_eq!(expanded, "a/file.txt}");
+    }
+
     #[test]
     fn all_placeholders() {
         use Token::*;
diff --git a/tests/tests.rs b/tests/tests.rs
index 191447b5e..cdca57a30 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -1755,6 +1755,13 @@ fn format() {
         parent=one/two/three
         parent=one/two/three",
     );
+
+    // A placeholder immediately followed by a literal '}' is still expanded,
+    // with the '}' kept as trailing literal text (see issue with `{}}`).
+    te.assert_output(
+        &["^a\\.foo$", "--format", "{}}", "--path-separator=/"],
+        "a.foo}",
+    );
 }
 
 /// Shell script execution (--exec)