From d5a2d9205dd4f8ead3359b2ee59207d3f4e80c54 Mon Sep 17 00:00:00 2001
From: Ivan Bondarev <ibond84@googlemail.com>
Date: Sun, 12 Mar 2023 11:59:02 +0100
Subject: [PATCH] #2813

---
 .../PascalABCParserNewSaushkin/SemanticRules.cs    | 14 ++++++++++++--
 TestSuite/errors/err0519_format_string.pas         |  3 +++
 TestSuite/formatstring9.pas                        |  6 ++++++
 3 files changed, 21 insertions(+), 2 deletions(-)
 create mode 100644 TestSuite/errors/err0519_format_string.pas
 create mode 100644 TestSuite/formatstring9.pas

diff --git a/Parsers/PascalABCParserNewSaushkin/SemanticRules.cs b/Parsers/PascalABCParserNewSaushkin/SemanticRules.cs
index b0661c413..2b48ab4ef 100644
--- a/Parsers/PascalABCParserNewSaushkin/SemanticRules.cs
+++ b/Parsers/PascalABCParserNewSaushkin/SemanticRules.cs
@@ -489,11 +489,21 @@ namespace GPPGParserScanner
                     }
                         
                 }
+                
                 string str2 = sb.ToString();
                 if (str2.Trim().EndsWith("{"))
                 {
-                    parsertools.errors.Add(new bad_format_string(parsertools.CurrentFileName, str.source_context, str));
-                    return str;
+                    int cnt = 0;
+                    string tmp = str2.Trim();
+                    for (var i = 0; i < tmp.Length; i++)
+                        if (tmp[i] == '{')
+                            cnt++;
+                    if (cnt % 2 == 1)
+                    {
+                        parsertools.errors.Add(new bad_format_string(parsertools.CurrentFileName, str.source_context, str));
+                        return str;
+                    }
+                        
                 }
                 mc.parameters.Add(new string_const(str2, str.source_context), str.source_context);
                 for (int i = 0; i < vars.Count; i++)
diff --git a/TestSuite/errors/err0519_format_string.pas b/TestSuite/errors/err0519_format_string.pas
new file mode 100644
index 000000000..0b89595c4
--- /dev/null
+++ b/TestSuite/errors/err0519_format_string.pas
@@ -0,0 +1,3 @@
+begin
+  var s := $'{{{';
+end.
\ No newline at end of file
diff --git a/TestSuite/formatstring9.pas b/TestSuite/formatstring9.pas
new file mode 100644
index 000000000..a532d2f2d
--- /dev/null
+++ b/TestSuite/formatstring9.pas
@@ -0,0 +1,6 @@
+begin
+  var s := $'{{';
+  assert(s = '{');
+  s := $'{{{{';
+  assert(s = '{{');
+end.
\ No newline at end of file