avoid overwrite user CMakePresets

conan/tools/cmake/presets.py

@@ -43,6 +43,13 @@ def generate(conanfile, toolchain_file, generator, cache_variables, preset_prefi
 
         preset_path = os.path.join(conanfile.generators_folder, "CMakePresets.json")
         multiconfig = is_multi_configuration(generator)
+        if os.path.exists(preset_path):
+            data = json.loads(load(preset_path))
+            if "conan" not in data.get("vendor", {}):
+                # The file is not ours, we cannot overwrite it
+                raise ConanException("Existing CMakePresets.json not generated by Conan cannot be "
+                                     "overwritten.\nUse --output-folder or define a 'layout' to "
+                                     "avoid collision with your CMakePresets.json")
         if os.path.exists(preset_path) and multiconfig:
             data = json.loads(load(preset_path))
             build_preset = _CMakePresets._build_and_test_preset_fields(conanfile, multiconfig,

conans/test/integration/toolchains/cmake/test_cmaketoolchain.py

@@ -1176,3 +1176,13 @@ def generate(self):
     assert 'string(APPEND CONAN_C_FLAGS " extra_cflags cflags")' in toolchain
     assert 'string(APPEND CONAN_SHARED_LINKER_FLAGS " extra_sharedlinkflags sharedlinkflags")' in toolchain
     assert 'string(APPEND CONAN_EXE_LINKER_FLAGS " extra_exelinkflags exelinkflags")' in toolchain
+
+
+def test_avoid_ovewrite_user_cmakepresets():
+    # https://github.com/conan-io/conan/issues/15052
+    c = TestClient()
+    c.save({"conanfile.txt": "",
+            "CMakePresets.json": "{}"})
+    c.run('install . -g CMakeToolchain', assert_error=True)
+    assert "Error in generator 'CMakeToolchain': Existing CMakePresets.json not generated" in c.out
+    assert "Use --output-folder or define a 'layout' to avoid collision" in c.out