From b194ce55dc39daea339f32f3c8cb0c844ff33a0e Mon Sep 17 00:00:00 2001
From: Ferenc Gerlits <fgerlits@gmail.com>
Date: Sun, 29 Dec 2024 21:00:42 +0100
Subject: [PATCH] MINIFICPP-2506 Fix a gcc warning
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There is a GCC warning in PythonLibLoader.cpp, so minifi does not compile with ENABLE_PYTHON_SCRIPTING and MINIFI_FAIL_ON_WARNINGS both ON.

The warning:
```
/home/runner/work/nifi-minifi-cpp/nifi-minifi-cpp/extensions/python/pythonlibloader/PythonLibLoader.cpp: In static member function ‘static std::string PythonLibLoader::execCommand(const std::string&)’:
/home/runner/work/nifi-minifi-cpp/nifi-minifi-cpp/extensions/python/pythonlibloader/PythonLibLoader.cpp:78:44: error: ignoring attributes on template argument ‘int (*)(FILE*)’ [-Werror=ignored-attributes]
 78 | std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd.c_str(), "r"), pclose);
 | ^
```

Closes #1912

Signed-off-by: Marton Szasz <szaszm@apache.org>
---
 extensions/python/pythonlibloader/PythonLibLoader.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/extensions/python/pythonlibloader/PythonLibLoader.cpp b/extensions/python/pythonlibloader/PythonLibLoader.cpp
index 6407982e37..8c2d7ec551 100644
--- a/extensions/python/pythonlibloader/PythonLibLoader.cpp
+++ b/extensions/python/pythonlibloader/PythonLibLoader.cpp
@@ -75,7 +75,8 @@ class PythonLibLoader {
   static std::string execCommand(const std::string& cmd) {
     std::array<char, 128> buffer{};
     std::string result;
-    std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd.c_str(), "r"), pclose);
+    struct pclose_deleter { void operator()(FILE* file) noexcept { pclose(file); } };
+    std::unique_ptr<FILE, pclose_deleter> pipe{popen(cmd.c_str(), "r")};
     if (!pipe) {
       return "";
     }