From d111a6a60d3535933e4b6eba7007519b3e9d6835 Mon Sep 17 00:00:00 2001
From: Lars-Dominik Braun <lars@6xq.net>
Date: Mon, 1 Sep 2025 17:05:23 +0200
Subject: [PATCH] guix: toml: Fix keys with embedded escape codes.
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Quoted keys are treated by the specification like ordinary strings,
so escape codes must be handled as well.

* guix/build/toml.scm (eval-value): Move string escape handling…
(eval-value): …here.
(eval-toml-file): Un-escape quoted keys.
* tests/toml.scm ("parse-toml: Quoted keys with escapes"): New testcase.

Fixes: guix/guix#2414
Change-Id: I612e415cc93207bbdd18b6ec8279255fee16670a
Signed-off-by: Sharlatan Hellseher <sharlatanus@gmail.com>
---
 guix/build/toml.scm | 30 ++++++++++++++++++------------
 tests/toml.scm      |  6 ++++++
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/guix/build/toml.scm b/guix/build/toml.scm
index a9be0887e7..b43fe4bb8b 100644
--- a/guix/build/toml.scm
+++ b/guix/build/toml.scm
@@ -361,6 +361,21 @@ the list KEY. For instance a KEY (a b) would retrieve alist[a][b]."
                (string->number minute)) 60))
          (#f #f)))))
 
+  (define (eval-string value)
+    "Turn a list of string tokens into an actual, flat string value by
+evaluating escape codes."
+    (apply string-append
+           (map (match-lambda
+                 (('escaped "\"") "\"")
+                 (('escaped "\\") "\\")
+                 (('escaped "b") "\b")
+                 (('escaped "t") "\t")
+                 (('escaped "n") "\n")
+                 (('escaped (? (lambda (x) (>= (string-length x) 4)) u))
+                  (list->string (list (integer->char (string->number u 16)))))
+                 ((? string? s) s))
+                (keyword-flatten '(escaped) value))))
+
   (define (eval-value value)
     "Evaluate right-hand-side of 'keyval token (i.e., a value)."
     (match value
@@ -395,17 +410,7 @@ the list KEY. For instance a KEY (a b) would retrieve alist[a][b]."
       (('local-time rest ...)
        (eval-date rest))
       (('string str ...)
-       (apply string-append
-              (map (match-lambda
-                    (('escaped "\"") "\"")
-                    (('escaped "\\") "\\")
-                    (('escaped "b") "\b")
-                    (('escaped "t") "\t")
-                    (('escaped "n") "\n")
-                    (('escaped (? (lambda (x) (>= (string-length x) 4)) u))
-                     (list->string (list (integer->char (string->number u 16)))))
-                    ((? string? s) s))
-                   (keyword-flatten '(escaped) str))))
+       (eval-string str))
       ('string "")
       (('array tails ...)
        (map eval-value (keyword-flatten '(boolean integer float string array
@@ -427,7 +432,8 @@ the list KEY. For instance a KEY (a b) would retrieve alist[a][b]."
      (map
       (match-lambda
         (('simple-key 'quoted-key) "")
-        (('simple-key ('quoted-key k)) k)
+        ;; Quoted keys are just ordinary strings and can contain escape codes.
+        (('simple-key ('quoted-key rest ...)) (eval-string rest))
         (('simple-key (? string? k)) k)
         (other (raise-exception `(invalid-simple-key ,other))))
       (keyword-flatten '(simple-key) keys)))
diff --git a/tests/toml.scm b/tests/toml.scm
index 64bc667f0c..955a9967b2 100644
--- a/tests/toml.scm
+++ b/tests/toml.scm
@@ -54,6 +54,12 @@ bare-key = \"value\"
 'key2' = \"value\"
 'quoted \"value\"' = \"value\""))
 
+(test-equal "parse-toml: Quoted keys with escapes"
+  '(("key \\ with \n escapes" . "value")
+    ("key" ("with \t escapes" ("and \n dots" . "value"))))
+  (parse-toml "\"key \\\\ with \\n escapes\" = \"value\"
+key.\"with \\t escapes\".\"and \\n dots\" = \"value\""))
+
 (test-equal "parse-toml: No key"
   #f
   (parse-toml "= \"no key name\""))