From 8979e7aaab8e736b6c078a489dcdd6e6fe879c9d Mon Sep 17 00:00:00 2001
From: Marc Chevrier <marc.chevrier@gmail.com>
Date: Fri, 25 Oct 2024 10:29:03 +0200
Subject: [PATCH] add_custom_command(DEPFILE): avoid duplicate entries in
 dependencies

Fixes: #26399
---
 Source/cmDependsCompiler.cxx                           | 9 ++-------
 Tests/RunCMake/BuildDepends/CustomCommandDepfile.cmake | 9 +++++++++
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/Source/cmDependsCompiler.cxx b/Source/cmDependsCompiler.cxx
index 17ec43bf14..408f19f5c7 100644
--- a/Source/cmDependsCompiler.cxx
+++ b/Source/cmDependsCompiler.cxx
@@ -4,7 +4,6 @@
 #include "cmDependsCompiler.h"
 
 #include <algorithm>
-#include <iterator>
 #include <map>
 #include <string>
 #include <unordered_set>
@@ -111,13 +110,9 @@ bool cmDependsCompiler::CheckDependencies(
           // copy depends for each target, except first one, which can be
           // moved
           for (auto index = entry.rules.size() - 1; index > 0; --index) {
-            auto& rule_deps = dependencies[entry.rules[index]];
-            rule_deps.insert(rule_deps.end(), depends.cbegin(),
-                             depends.cend());
+            dependencies[entry.rules[index]] = depends;
           }
-          auto& rule_deps = dependencies[entry.rules.front()];
-          std::move(depends.cbegin(), depends.cend(),
-                    std::back_inserter(rule_deps));
+          dependencies[entry.rules.front()] = std::move(depends);
         }
       } else {
         if (format == "msvc"_s) {
diff --git a/Tests/RunCMake/BuildDepends/CustomCommandDepfile.cmake b/Tests/RunCMake/BuildDepends/CustomCommandDepfile.cmake
index c3725a4d1a..331d21d828 100644
--- a/Tests/RunCMake/BuildDepends/CustomCommandDepfile.cmake
+++ b/Tests/RunCMake/BuildDepends/CustomCommandDepfile.cmake
@@ -77,5 +77,14 @@ if(check_step EQUAL 3)
     \"${CMAKE_BINARY_DIR}/step3.timestamp|$<TARGET_FILE:subexe>\"
     \"${CMAKE_BINARY_DIR}/step3.timestamp|$<TARGET_FILE:sublib>\"
     )
+
+  if (RunCMake_GENERATOR MATCHES \"Make\")
+    file(STRINGS \"${CMAKE_BINARY_DIR}/CMakeFiles/topcc.dir/compiler_depend.internal\" deps REGEX \"^.*topccdep\\\\.txt$\")
+    list(LENGTH deps count)
+    if (NOT count EQUAL 1)
+       string(APPEND RunCMake_TEST_FAILED \"dependencies are duplicated\\n\")
+       set(RunCMake_TEST_FAILED \"\${RunCMake_TEST_FAILED}\" PARENT_SCOPE)
+    endif()
+  endif()
 endif()
 ")