From dbe7c4ef52b0e0e93c1889ef61f800f93bd07947 Mon Sep 17 00:00:00 2001
From: John Bytheway <52664+jbytheway@users.noreply.github.com>
Date: Tue, 7 Jun 2022 19:53:33 -0400
Subject: [PATCH 1/2] Enable bugprone-unhandled-self-assignment

This check looks for suspicious assignment operators that might not
correctly handle self-assignment.  In practice it is a bit prone to
false-positives, but we have so few assignment operators in general
that's not a big deal.

Also enable cert-oop54-cpp which is essentially the same check.  Tweak
its configuration so that it doesn't have more false positives.

Suppress these warnings in one place and fix them in another.
---
 .clang-tidy            | 8 ++++----
 src/json.cpp           | 1 +
 src/safe_reference.cpp | 6 ++++--
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/.clang-tidy b/.clang-tidy
index 2997e067c1edd..d6734b4ba646b 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -51,8 +51,6 @@ readability-*,\
 -bugprone-narrowing-conversions,\
 -bugprone-redundant-branch-condition,\
 -bugprone-signed-char-misuse,\
--bugprone-unhandled-self-assignment,\
--cert-oop54-cpp,\
 -cert-str34-c,\
 -clang-analyzer-core.CallAndMessage,\
 -clang-analyzer-deadcode.DeadStores,\
@@ -86,9 +84,11 @@ WarningsAsErrors: '*'
 HeaderFilterRegex: '(src|test|tools).*'
 FormatStyle:     none
 CheckOptions:
-  - key: readability-uppercase-literal-suffix.NewSuffixes
-    value: 'L;UL;LL;ULL'
   - key: cata-text-style.EscapeUnicode
     value: 0
+  - key: cert-oop54-cpp.WarnOnlyIfThisHasSuspiciousField
+    value: true
+  - key: readability-uppercase-literal-suffix.NewSuffixes
+    value: 'L;UL;LL;ULL'
 
 # vim:tw=0
diff --git a/src/json.cpp b/src/json.cpp
index 05c3cb199a39d..7b9e96e52e901 100644
--- a/src/json.cpp
+++ b/src/json.cpp
@@ -486,6 +486,7 @@ JsonArray::JsonArray( const JsonArray &ja )
     final_separator = ja.final_separator;
 }
 
+// NOLINTNEXTLINE(bugprone-unhandled-self-assignment,cert-oop54-cpp)
 JsonArray &JsonArray::operator=( const JsonArray &ja )
 {
     jsin = ja.jsin;
diff --git a/src/safe_reference.cpp b/src/safe_reference.cpp
index 6dd4c6e6ee924..2264915a7b5a1 100644
--- a/src/safe_reference.cpp
+++ b/src/safe_reference.cpp
@@ -19,9 +19,11 @@ safe_reference_anchor::safe_reference_anchor( safe_reference_anchor && ) noexcep
     safe_reference_anchor()
 {}
 
-safe_reference_anchor &safe_reference_anchor::operator=( const safe_reference_anchor & )
+safe_reference_anchor &safe_reference_anchor::operator=( const safe_reference_anchor &other )
 {
-    impl = std::make_shared<empty>();
+    if( this != &other ) {
+        impl = std::make_shared<empty>();
+    }
     return *this;
 }
 

From b8a698671c169b5e380ccfbf152aa42f016e1501 Mon Sep 17 00:00:00 2001
From: John Bytheway <52664+jbytheway@users.noreply.github.com>
Date: Tue, 7 Jun 2022 19:56:16 -0400
Subject: [PATCH 2/2] Simplify JsonArray copy constructor

Implement it in terms of its assignment operator to reduce code
duplication.
---
 src/json.cpp | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/src/json.cpp b/src/json.cpp
index 7b9e96e52e901..51311a47601dc 100644
--- a/src/json.cpp
+++ b/src/json.cpp
@@ -478,12 +478,7 @@ JsonArray::JsonArray( JsonIn &j )
 
 JsonArray::JsonArray( const JsonArray &ja )
 {
-    jsin = ja.jsin;
-    start = ja.start;
-    index = 0;
-    positions = ja.positions;
-    end_ = ja.end_;
-    final_separator = ja.final_separator;
+    *this = ja;
 }
 
 // NOLINTNEXTLINE(bugprone-unhandled-self-assignment,cert-oop54-cpp)