From 53ea48874167f0a6d787123934fb3d8be6f945b3 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 23 Jul 2026 10:25:48 +0000
Subject: [PATCH] C++: Verify [\b] is backspace inside character classes

---
 cpp/ql/test/library-tests/regex/parse.expected  | 5 +++++
 cpp/ql/test/library-tests/regex/regexp.cpp      | 1 +
 cpp/ql/test/library-tests/regex/regexp.expected | 3 +++
 3 files changed, 9 insertions(+)

diff --git a/cpp/ql/test/library-tests/regex/parse.expected b/cpp/ql/test/library-tests/regex/parse.expected
index 148b8af0ac5..80833567ffc 100644
--- a/cpp/ql/test/library-tests/regex/parse.expected
+++ b/cpp/ql/test/library-tests/regex/parse.expected
@@ -128,6 +128,8 @@
 
 #-----| [RegExpConstant, RegExpNormalChar] A-F]
 
+#-----| [RegExpConstant, RegExpEscape] \b
+
 #-----| [RegExpConstant, RegExpNormalChar] |
 
 #-----| [RegExpConstant, RegExpNormalChar] -
@@ -378,6 +380,9 @@
 #-----| 0 -> [RegExpConstant, RegExpNormalChar] [
 #-----| 1 -> [RegExpCharacterRange] a-f
 
+#-----| [RegExpCharacterClass] [\b]
+#-----| 0 -> [RegExpConstant, RegExpEscape] \b
+
 #-----| [RegExpCharacterClass] [|]
 #-----| 0 -> [RegExpConstant, RegExpNormalChar] |
 
diff --git a/cpp/ql/test/library-tests/regex/regexp.cpp b/cpp/ql/test/library-tests/regex/regexp.cpp
index 15e35eb0ca2..a1e1acb11c5 100644
--- a/cpp/ql/test/library-tests/regex/regexp.cpp
+++ b/cpp/ql/test/library-tests/regex/regexp.cpp
@@ -37,6 +37,7 @@ std::regex r_cc7("[]]");   // MRI gives a warning, but accepts this as matching
 std::regex r_cc8("[^]]"); // MRI gives a warning, but accepts this as matching anything except ']'
 std::regex r_cc9("[^-]");
 std::regex r_cc10("[|]");
+std::regex r_cc11("[\\b]");
 
 // Nested character classes (BAD - not parsed correctly)
 std::regex r_nested("[[a-f]A-F]");
diff --git a/cpp/ql/test/library-tests/regex/regexp.expected b/cpp/ql/test/library-tests/regex/regexp.expected
index 8bde18a3aa8..a56d5466316 100644
--- a/cpp/ql/test/library-tests/regex/regexp.expected
+++ b/cpp/ql/test/library-tests/regex/regexp.expected
@@ -67,6 +67,7 @@ term
 | file://:0:0:0:0 | [[a-f] | RegExpCharacterClass |
 | file://:0:0:0:0 | [[a-f]A-F] | RegExpSequence |
 | file://:0:0:0:0 | [\\0] | RegExpCharacterClass |
+| file://:0:0:0:0 | [\\b] | RegExpCharacterClass |
 | file://:0:0:0:0 | [\\cZ] | RegExpCharacterClass |
 | file://:0:0:0:0 | [\\w] | RegExpCharacterClass |
 | file://:0:0:0:0 | [\\w]+ | RegExpPlus |
@@ -87,6 +88,7 @@ term
 | file://:0:0:0:0 | \\[ | RegExpConstant,RegExpEscape |
 | file://:0:0:0:0 | \\[\\][123] | RegExpSequence |
 | file://:0:0:0:0 | \\] | RegExpConstant,RegExpEscape |
+| file://:0:0:0:0 | \\b | RegExpConstant,RegExpEscape |
 | file://:0:0:0:0 | \\b | RegExpSpecialChar |
 | file://:0:0:0:0 | \\b!a\\B | RegExpSequence |
 | file://:0:0:0:0 | \\cA | RegExpConstant,RegExpEscape |
@@ -216,6 +218,7 @@ regExpNormalCharValue
 | file://:0:0:0:0 | \\W | W |
 | file://:0:0:0:0 | \\[ | [ |
 | file://:0:0:0:0 | \\] | ] |
+| file://:0:0:0:0 | \\b | b |
 | file://:0:0:0:0 | \\cA | cA |
 | file://:0:0:0:0 | \\cZ | cZ |
 | file://:0:0:0:0 | \\d | d |