From 5cbe81dae2fdf2ab80bd4ef67bcce3e01a37bca8 Mon Sep 17 00:00:00 2001
From: Fabian Kosmale <fabian.kosmale@qt.io>
Date: Tue, 7 May 2024 09:45:39 +0200
Subject: [PATCH] QLibraryInfo: Refactor in preparation of multiple entries
 (1/2)

Extract the path normalization into a helper function, and use
qScopeGuard for leaving QSetting's group.

Moreover, slightly modernize the code by using sliced instead of mid,
and by using the more appropriate qEnvironmentVariable over getenv (our
target is a QString, and the variable contains user text).

Change-Id: I08e600782864684f10ff03451c789e59cdb8febf
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by:  Alexey Edelev <alexey.edelev@qt.io>
---
 src/corelib/global/qlibraryinfo.cpp | 57 +++++++++++++++--------------
 1 file changed, 30 insertions(+), 27 deletions(-)

diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
index 1b03733d2a..d0a537f778 100644
--- a/src/corelib/global/qlibraryinfo.cpp
+++ b/src/corelib/global/qlibraryinfo.cpp
@@ -523,6 +523,34 @@ QString QLibraryInfo::path(LibraryPath p)
 }
 
 
+static QString normalizePath(QString ret)
+{
+    qsizetype startIndex = 0;
+    /* We support placeholders of the form $(<ENV_VAR>) in qt.conf.
+       The loop below tries to find all such placeholders, and replaces
+       them with the actual value of the ENV_VAR environment variable
+     */
+    while (true) {
+        startIndex = ret.indexOf(u'$', startIndex);
+        if (startIndex < 0)
+            break;
+        if (ret.size() < startIndex + 3)
+            break;
+        if (ret.at(startIndex + 1) != u'(') {
+            startIndex++;
+            continue;
+        }
+        qsizetype endIndex = ret.indexOf(u')', startIndex + 2);
+        if (endIndex < 0)
+            break;
+        auto envVarName = QStringView{ret}.sliced(startIndex + 2, endIndex - startIndex - 2);
+        QString value = qEnvironmentVariable(envVarName.toLocal8Bit().constData());
+        ret.replace(startIndex, endIndex - startIndex + 1, value);
+        startIndex += value.size();
+    }
+    return QDir::fromNativeSeparators(ret);
+};
+
 /*
     Returns the path specified by \a p.
 
@@ -543,6 +571,7 @@ QString QLibraryInfoPrivate::path(QLibraryInfo::LibraryPath p, UsageMode usageMo
             QSettings *config = QLibraryInfoPrivate::configuration();
             Q_ASSERT(config != nullptr);
             config->beginGroup("Paths"_L1);
+            auto cleanup = qScopeGuard([&]() { config->endGroup(); });
 
             if (li.fallbackKey.isNull()) {
                 ret = config->value(li.key, li.defaultValue).toString();
@@ -553,33 +582,7 @@ QString QLibraryInfoPrivate::path(QLibraryInfo::LibraryPath p, UsageMode usageMo
                 ret = v.toString();
             }
 
-            qsizetype startIndex = 0;
-            /* We support placeholders of the form $(<ENV_VAR>) in qt.conf.
-               The loop below tries to find all such placeholders, and replaces
-               them with the actual value of the ENV_VAR environment variable
-             */
-            while (true) {
-                startIndex = ret.indexOf(u'$', startIndex);
-                if (startIndex < 0)
-                    break;
-                if (ret.size() < startIndex + 3)
-                    break;
-                if (ret.at(startIndex + 1) != u'(') {
-                    startIndex++;
-                    continue;
-                }
-                qsizetype endIndex = ret.indexOf(u')', startIndex + 2);
-                if (endIndex < 0)
-                    break;
-                auto envVarName = QStringView{ret}.mid(startIndex + 2, endIndex - startIndex - 2);
-                QString value = QString::fromLocal8Bit(qgetenv(envVarName.toLocal8Bit().constData()));
-                ret.replace(startIndex, endIndex - startIndex + 1, value);
-                startIndex += value.size();
-            }
-
-            config->endGroup();
-
-            ret = QDir::fromNativeSeparators(ret);
+            ret = normalizePath(std::move(ret));
         }
     }
 #endif // settings