feat: Add tilde expansion for home directory paths

Enables using ~ and ~/path in configurations instead of hard-coded
absolute paths, making settings portable across users.

- Add Utils::Fs::expandTilde() function
- Integrate tilde expansion in session path handling
- Support category path tilde expansion
- Add comprehensive test coverage

src/base/bittorrent/sessionimpl.cpp

@@ -552,8 +552,8 @@ SessionImpl::SessionImpl(QObject *parent)
     , m_storedTags(BITTORRENT_SESSION_KEY(u"Tags"_s))
     , m_shareLimitAction(BITTORRENT_SESSION_KEY(u"ShareLimitAction"_s), ShareLimitAction::Stop
         , [](const ShareLimitAction action) { return (action == ShareLimitAction::Default) ? ShareLimitAction::Stop : action; })
-    , m_savePath(BITTORRENT_SESSION_KEY(u"DefaultSavePath"_s), specialFolderLocation(SpecialFolder::Downloads))
-    , m_downloadPath(BITTORRENT_SESSION_KEY(u"TempPath"_s), (savePath() / Path(u"temp"_s)))
+    , m_savePath(BITTORRENT_SESSION_KEY(u"DefaultSavePath"_s), specialFolderLocation(SpecialFolder::Downloads), Utils::Fs::expandTilde)
+    , m_downloadPath(BITTORRENT_SESSION_KEY(u"TempPath"_s), (savePath() / Path(u"temp"_s)), Utils::Fs::expandTilde)
     , m_isDownloadPathEnabled(BITTORRENT_SESSION_KEY(u"TempPathEnabled"_s), false)
     , m_isSubcategoriesEnabled(BITTORRENT_SESSION_KEY(u"SubcategoriesEnabled"_s), false)
     , m_useCategoryPathsInManualMode(BITTORRENT_SESSION_KEY(u"UseCategoryPathsInManualMode"_s), false)
@@ -1006,6 +1006,14 @@ bool SessionImpl::addCategory(const QString &name, const CategoryOptions &option
     if (!isValidCategoryName(name) || m_categories.contains(name))
         return false;
 
+    // Expand tildes in category save path
+    CategoryOptions expandedOptions = options;
+    expandedOptions.savePath = Utils::Fs::expandTilde(options.savePath);
+    if (expandedOptions.downloadPath.has_value())
+    {
+        expandedOptions.downloadPath->path = Utils::Fs::expandTilde(expandedOptions.downloadPath->path);
+    }
+
     if (isSubcategoriesEnabled())
     {
         for (const QString &parent : asConst(expandCategory(name)))
@@ -1018,7 +1026,7 @@ bool SessionImpl::addCategory(const QString &name, const CategoryOptions &option
         }
     }
 
-    m_categories[name] = options;
+    m_categories[name] = expandedOptions;
     storeCategories();
     emit categoryAdded(name);
 
@@ -1031,8 +1039,16 @@ bool SessionImpl::editCategory(const QString &name, const CategoryOptions &optio
     if (it == m_categories.end())
         return false;
 
+    // Expand tildes in category save path
+    CategoryOptions expandedOptions = options;
+    expandedOptions.savePath = Utils::Fs::expandTilde(options.savePath);
+    if (expandedOptions.downloadPath.has_value())
+    {
+        expandedOptions.downloadPath->path = Utils::Fs::expandTilde(expandedOptions.downloadPath->path);
+    }
+
     CategoryOptions &currentOptions = it.value();
-    if (options == currentOptions)
+    if (expandedOptions == currentOptions)
         return false;
 
     if (isDisableAutoTMMWhenCategorySavePathChanged())
@@ -1047,7 +1063,7 @@ bool SessionImpl::editCategory(const QString &name, const CategoryOptions &optio
         }
     }
 
-    currentOptions = options;
+    currentOptions = expandedOptions;
     storeCategories();
 
     for (TorrentImpl *const torrent : asConst(m_torrents))
@@ -3281,7 +3297,8 @@ void SessionImpl::removeTorrentsQueue()
 
 void SessionImpl::setSavePath(const Path &path)
 {
-    const auto newPath = (path.isAbsolute() ? path : (specialFolderLocation(SpecialFolder::Downloads) / path));
+    const Path expandedPath = Utils::Fs::expandTilde(path);
+    const auto newPath = (expandedPath.isAbsolute() ? expandedPath : (specialFolderLocation(SpecialFolder::Downloads) / expandedPath));
     if (newPath == m_savePath)
         return;
 
@@ -3321,7 +3338,8 @@ void SessionImpl::setSavePath(const Path &path)
 
 void SessionImpl::setDownloadPath(const Path &path)
 {
-    const Path newPath = (path.isAbsolute() ? path : (savePath() / Path(u"temp"_s) / path));
+    const Path expandedPath = Utils::Fs::expandTilde(path);
+    const Path newPath = (expandedPath.isAbsolute() ? expandedPath : (savePath() / Path(u"temp"_s) / expandedPath));
     if (newPath == m_downloadPath)
         return;
 
@@ -5581,7 +5599,15 @@ void SessionImpl::loadCategories()
     for (auto it = jsonObj.constBegin(); it != jsonObj.constEnd(); ++it)
     {
         const QString &categoryName = it.key();
-        const auto categoryOptions = CategoryOptions::fromJSON(it.value().toObject());
+        auto categoryOptions = CategoryOptions::fromJSON(it.value().toObject());
+        
+        // Expand tildes in loaded category paths
+        categoryOptions.savePath = Utils::Fs::expandTilde(categoryOptions.savePath);
+        if (categoryOptions.downloadPath.has_value())
+        {
+            categoryOptions.downloadPath->path = Utils::Fs::expandTilde(categoryOptions.downloadPath->path);
+        }
+        
         m_categories[categoryName] = categoryOptions;
     }
 }

src/base/utils/fs.cpp

@@ -219,6 +219,33 @@ Path Utils::Fs::tempPath()
     return path;
 }
 
+Path Utils::Fs::expandTilde(const Path &path)
+{
+    if (path.isEmpty())
+        return path;
+        
+    const QString pathStr = path.data();
+    
+    // Check if path starts with ~ (tilde)
+    if (pathStr.startsWith(u'~'))
+    {
+        if (pathStr.size() == 1)
+        {
+            // Just ~ means home directory
+            return homePath();
+        }
+        else if (pathStr.at(1) == u'/')
+        {
+            // ~/something means home directory + something
+            return homePath() / Path(pathStr.sliced(2));
+        }
+        // ~username is not supported for simplicity and security
+    }
+    
+    // Return original path if no tilde expansion needed
+    return path;
+}
+
 bool Utils::Fs::isRegularFile(const Path &path)
 {
     std::error_code ec;

src/base/utils/fs.h

@@ -71,4 +71,5 @@ namespace Utils::Fs
 
     Path homePath();
     Path tempPath();
+    Path expandTilde(const Path &path);
 }

test/CMakeLists.txt

@@ -14,6 +14,7 @@ set(testFiles
     testglobal.cpp
     testorderedset.cpp
     testpath.cpp
+    testtildeexpansion.cpp
     testutilsbytearray.cpp
     testutilscompare.cpp
     testutilsdatetime.cpp

test/testtildeexpansion.cpp

@@ -0,0 +1,45 @@
+#include <QDir>
+#include <QObject>
+#include <QString>
+#include <QTest>
+
+#include "base/path.h"
+#include "base/utils/fs.h"
+
+class TestTildeExpansion : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void testExpandTilde_data();
+    void testExpandTilde();
+};
+
+void TestTildeExpansion::testExpandTilde_data()
+{
+    QTest::addColumn<QString>("input");
+    QTest::addColumn<QString>("expected");
+    
+    const QString homeDir = QDir::homePath();
+    
+    QTest::newRow("tilde only") << u"~"_s << homeDir;
+    QTest::newRow("tilde with path") << u"~/Downloads"_s << (homeDir + u"/Downloads"_s);
+    QTest::newRow("tilde with nested path") << u"~/Documents/qBittorrent"_s << (homeDir + u"/Documents/qBittorrent"_s);
+    QTest::newRow("absolute path") << u"/absolute/path"_s << u"/absolute/path"_s;
+    QTest::newRow("relative path") << u"relative/path"_s << u"relative/path"_s;
+    QTest::newRow("empty path") << u""_s << u""_s;
+}
+
+void TestTildeExpansion::testExpandTilde()
+{
+    QFETCH(QString, input);
+    QFETCH(QString, expected);
+    
+    const Path inputPath(input);
+    const Path expandedPath = Utils::Fs::expandTilde(inputPath);
+    
+    QCOMPARE(expandedPath.data(), expected);
+}
+
+QTEST_APPLESS_MAIN(TestTildeExpansion)
+#include "testtildeexpansion.moc"