From 63cb43d56cab5cea439890056359434d89c2b611 Mon Sep 17 00:00:00 2001
From: Lars-Dominik Braun <lars@6xq.net>
Date: Sat, 4 May 2024 09:43:11 +0200
Subject: [PATCH] guix: toml: Fix parsing empty strings in arrays.

Change-Id: Id14d4008391a01820ade754fa9c2ca8e88b8c7f9
---
 guix/build/toml.scm | 15 +++++++++------
 tests/toml.scm      | 27 +++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/guix/build/toml.scm b/guix/build/toml.scm
index d5ea01d001..81b54fa5b7 100644
--- a/guix/build/toml.scm
+++ b/guix/build/toml.scm
@@ -97,7 +97,7 @@ (define-peg-pattern string all (or ml-basic-string
 
 ;; Basic String
 (define-peg-pattern basic-string body (and (ignore "\"")
-                                           (* basic-char)
+                                           (or (+ basic-char) "")
                                            (ignore "\"")))
 (define-peg-pattern basic-char body (or basic-unescaped escaped))
 (define-peg-pattern basic-unescaped body (or wschar
@@ -116,9 +116,11 @@ (define-peg-pattern escaped all (and
 
 ;; Multiline Basic String
 (define-peg-pattern ml-basic-string body (and
-                                           ml-basic-string-delim
+                                          ml-basic-string-delim
                                           (? ignore-newline)
-                                          ml-basic-body
+                                          ;; Force the result of the empty string
+                                          ;; to be a string, not no token.
+                                          (and ml-basic-body "")
                                           ml-basic-string-delim))
 (define-peg-pattern ml-basic-string-delim none "\"\"\"")
 (define-peg-pattern ml-basic-body body (and
@@ -145,7 +147,7 @@ (define-peg-pattern mlb-escaped-nl none (and "\\" ws newline
 
 ;; Literal String
 (define-peg-pattern literal-string body (and (ignore "'")
-                                             (* literal-char)
+                                             (or (+ literal-char) "")
                                              (ignore "'")))
 (define-peg-pattern literal-char body (or "\x09"
                                           (range #\x20 #\x26)
@@ -156,7 +158,9 @@ (define-peg-pattern literal-char body (or "\x09"
 (define-peg-pattern ml-literal-string body (and
                                             ml-literal-string-delim
                                             (? ignore-newline)
-                                            ml-literal-body
+                                            ;; Force the result of the empty string
+                                            ;; to be a string, not no token.
+                                            (and ml-literal-body "")
                                             ml-literal-string-delim))
 (define-peg-pattern ml-literal-string-delim none "'''")
 (define-peg-pattern ml-literal-body body (and
@@ -475,4 +479,3 @@ (define (parse-toml-file file)
   "Parse and evaluate toml document from file FILE."
 
   (parse-toml (call-with-input-file file get-string-all)))
-
diff --git a/tests/toml.scm b/tests/toml.scm
index cd731cd2f0..cd8e4d2338 100644
--- a/tests/toml.scm
+++ b/tests/toml.scm
@@ -305,6 +305,33 @@ (define-module (test-toml)
   2, # this is ok
 ]"))
 
+(test-equal "parse-toml: Arrays of empty strings"
+ '(("empty1" "")
+   ("empty2" "" "")
+   ("empty3" "" "" "")
+   ("emptyraw1" "")
+   ("emptyraw2" "" "")
+   ("emptyraw3" "" "" "")
+   ("emptyml1" "")
+   ("emptyml2" "" "")
+   ("emptyml3" "" "" "")
+   ("emptyrawml1" "")
+   ("emptyrawml2" "" "")
+   ("emptyrawml3" "" "" ""))
+ (parse-toml "empty1 = [ \"\" ]
+empty2 = [ \"\", \"\" ]
+empty3 = [ \"\", \"\", \"\" ]
+emptyraw1 = [ '' ]
+emptyraw2 = [ '', '' ]
+emptyraw3 = [ '', '', '' ]
+emptyml1 = [ \"\"\"\"\"\" ]
+emptyml2 = [ \"\"\"\"\"\", \"\"\"\"\"\" ]
+emptyml3 = [ \"\"\"\"\"\", \"\"\"\"\"\", \"\"\"\"\"\" ]
+emptyrawml1 = [ '''''' ]
+emptyrawml2 = [ '''''', '''''' ]
+emptyrawml3 = [ '''''', '''''', '''''' ]
+"))
+
 (test-equal "parse-toml: Tables"
  '(("table-1" ("key1" . "some string")
               ("key2" . 123))