From c9bc5a076f293ebb1668debd02fc59f573e0ab38 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sun, 28 Feb 2021 21:43:51 +0100
Subject: [PATCH] Fixed #10014 (-U switch ignored when using
 --project=compile_commands.json and --force)

---
 lib/cppcheck.cpp               |  2 +-
 test/cli/test-more-projects.py | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 test/cli/test-more-projects.py

diff --git a/lib/cppcheck.cpp b/lib/cppcheck.cpp
index a80c3a1f9..b229971ca 100644
--- a/lib/cppcheck.cpp
+++ b/lib/cppcheck.cpp
@@ -489,7 +489,7 @@ unsigned int CppCheck::check(const ImportProject::FileSettings &fs)
     else
         temp.mSettings.userDefines += fs.cppcheckDefines();
     temp.mSettings.includePaths = fs.includePaths;
-    temp.mSettings.userUndefs = fs.undefs;
+    temp.mSettings.userUndefs.insert(fs.undefs.cbegin(), fs.undefs.cend());
     if (fs.standard.find("++") != std::string::npos)
         temp.mSettings.standards.setCPP(fs.standard);
     else if (!fs.standard.empty())
diff --git a/test/cli/test-more-projects.py b/test/cli/test-more-projects.py
new file mode 100644
index 000000000..48e50793a
--- /dev/null
+++ b/test/cli/test-more-projects.py
@@ -0,0 +1,34 @@
+
+# python -m pytest test-helloworld.py
+
+import os
+import tempfile
+from testutils import cppcheck
+
+
+def test_project_force_U():
+    # 10018
+    # -U does not work with compile_commands.json
+    with tempfile.TemporaryDirectory('10018') as temp_folder:
+        with open(os.path.join(temp_folder, 'bug1.cpp'), 'wt') as f:
+            f.write("""
+                    int x = 123 / 0;
+                    #ifdef MACRO1
+                    int y = 1000 / 0;
+                    #endif
+                    """)
+
+        compile_commands = os.path.join(temp_folder, 'compile_commands.json')
+
+        with open(compile_commands, 'wt') as f:
+            f.write('[ { "directory": "%s", "command": "c++ -o bug1.o -c bug1.cpp", "file": "bug1.cpp", "output": "bug1.o" } ]' % str(temp_folder))
+
+        # Without -U => both bugs are found
+        ret, stdout, stderr = cppcheck(['--project=' + compile_commands, '--force', '-rp=' + temp_folder, '--template=cppcheck1'])
+        assert (stderr == '[bug1.cpp:2]: (error) Division by zero.\n'
+                          '[bug1.cpp:4]: (error) Division by zero.\n')
+
+        # With -U => only first bug is found
+        ret, stdout, stderr = cppcheck(['--project=' + compile_commands, '--force', '-UMACRO1', '-rp=' + temp_folder, '--template=cppcheck1'])
+        assert stderr == '[bug1.cpp:2]: (error) Division by zero.\n'
+