From 0ab70d74fbdd1960a93a25bca9be8bea2dcdab4f Mon Sep 17 00:00:00 2001
From: Marek Blaha <mblaha@redhat.com>
Date: Fri, 7 Feb 2025 09:52:13 +0100
Subject: [PATCH 14/15] conf: Improve granularity of ConfigParser exceptions

In some cases, we need to distinguish between a missing config file and
one that exists but is unreadable (e.g., due to insufficient
permissions).

This patch introduces a new FileDoesNotExist exception class, which is a
more specific subclass of the existing CantOpenFile class. This ensures
that any existing workflows remain unaffected.

Upstream commit: b5d48a6
---
 libdnf/conf/ConfigParser.cpp         |  2 ++
 libdnf/conf/ConfigParser.hpp         |  3 +++
 libdnf/utils/iniparser/iniparser.cpp | 15 ++++++++++++++-
 libdnf/utils/iniparser/iniparser.hpp |  4 ++++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/libdnf/conf/ConfigParser.cpp b/libdnf/conf/ConfigParser.cpp
index 186acdc8..6ff110a7 100644
--- a/libdnf/conf/ConfigParser.cpp
+++ b/libdnf/conf/ConfigParser.cpp
@@ -271,6 +271,8 @@ void ConfigParser::read(const std::string & filePath)
     try {
         IniParser parser(filePath);
         ::libdnf::read(*this, parser);
+    } catch (const IniParser::FileDoesNotExist & e) {
+        throw FileDoesNotExist(e.what());
     } catch (const IniParser::CantOpenFile & e) {
         throw CantOpenFile(e.what());
     } catch (const IniParser::Exception & e) {
diff --git a/libdnf/conf/ConfigParser.hpp b/libdnf/conf/ConfigParser.hpp
index de8a0c9d..2d269147 100644
--- a/libdnf/conf/ConfigParser.hpp
+++ b/libdnf/conf/ConfigParser.hpp
@@ -55,6 +55,9 @@ public:
     struct CantOpenFile : public Exception {
         CantOpenFile(const std::string & what) : Exception(what) {}
     };
+    struct FileDoesNotExist : public CantOpenFile {
+        FileDoesNotExist(const std::string & what) : CantOpenFile(what) {}
+    };
     struct ParsingError : public Exception {
         ParsingError(const std::string & what) : Exception(what) {}
     };
diff --git a/libdnf/utils/iniparser/iniparser.cpp b/libdnf/utils/iniparser/iniparser.cpp
index 1109c120..3c537826 100644
--- a/libdnf/utils/iniparser/iniparser.cpp
+++ b/libdnf/utils/iniparser/iniparser.cpp
@@ -20,6 +20,9 @@
 
 #include "iniparser.hpp"
 
+#include <errno.h>
+#include <sys/stat.h>
+
 constexpr char DELIMITER = '\n';
 
 const char * IniParser::CantOpenFile::what() const noexcept
@@ -27,6 +30,11 @@ const char * IniParser::CantOpenFile::what() const noexcept
     return "IniParser: Can't open file";
 }
 
+const char * IniParser::FileDoesNotExist::what() const noexcept
+{
+    return "IniParser: File does not exist";
+}
+
 const char * IniParser::MissingSectionHeader::what() const noexcept
 {
     return "IniParser: Missing section header";
@@ -65,8 +73,13 @@ const char * IniParser::MissingEqual::what() const noexcept
 IniParser::IniParser(const std::string & filePath)
 : is(new std::ifstream(filePath))
 {
-    if (!(*is))
+    if (!(*is)) {
+        struct stat buffer;
+        if (stat(filePath.c_str(), &buffer) != 0 && errno == ENOENT) {
+            throw FileDoesNotExist();
+        }
         throw CantOpenFile();
+    }
     is->exceptions(std::ifstream::badbit);
     lineNumber = 0;
     lineReady = false;
diff --git a/libdnf/utils/iniparser/iniparser.hpp b/libdnf/utils/iniparser/iniparser.hpp
index a6635c6b..57494a18 100644
--- a/libdnf/utils/iniparser/iniparser.hpp
+++ b/libdnf/utils/iniparser/iniparser.hpp
@@ -46,6 +46,10 @@ public:
         CantOpenFile() {}
         const char * what() const noexcept override;
     };
+    struct FileDoesNotExist : public CantOpenFile {
+        FileDoesNotExist() {}
+        const char * what() const noexcept override;
+    };
     struct MissingSectionHeader : public Exception {
         MissingSectionHeader(int lineNumber) : Exception(lineNumber) {}
         const char * what() const noexcept override;
-- 
2.48.1