From 4983f08c47f45e82b991294f2ebe2824973c5535 Mon Sep 17 00:00:00 2001
From: Alexis Jeandet <alexis.jeandet@member.fsf.org>
Date: Tue, 17 Jun 2025 12:19:59 +0200
Subject: [PATCH] MesonProjectManager: fix loading previously configured
 projects

File watcher was not looking in build dir and wasn't updated when build
directory changed.
Also parsing should only happen on active build configurations.

Task-number: QTCREATORBUG-33071
Change-Id: I0c1ce95729472a7c08e029a322b7213acfe9c2f1
Reviewed-by: hjk <hjk@qt.io>
(cherry picked from commit 54a0c74ff8ad67800fcad2c01e2496c1d68314fb)
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
---
 .../mesonprojectmanager/mesonbuildsystem.cpp  | 34 ++++++++++++-------
 .../mesonprojectmanager/mesonbuildsystem.h    |  1 +
 2 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/src/plugins/mesonprojectmanager/mesonbuildsystem.cpp b/src/plugins/mesonprojectmanager/mesonbuildsystem.cpp
index 257e684db2d..80c4c5d3889 100644
--- a/src/plugins/mesonprojectmanager/mesonbuildsystem.cpp
+++ b/src/plugins/mesonprojectmanager/mesonbuildsystem.cpp
@@ -206,10 +206,8 @@ MesonBuildSystem::MesonBuildSystem(BuildConfiguration *bc)
     connect(bc, &BuildConfiguration::kitChanged, this, [this] {
         updateKit(kit());
     });
-    connect(bc, &MesonBuildConfiguration::buildDirectoryChanged, this, [this] {
-        updateKit(kit());
-        this->triggerParsing();
-    });
+    connect(bc, &MesonBuildConfiguration::buildDirectoryChanged, this,
+            &MesonBuildSystem::buildDirectoryChanged);
     connect(qobject_cast<MesonBuildConfiguration *>(bc),
             &MesonBuildConfiguration::parametersChanged, this, [this] {
         updateKit(kit());
@@ -231,14 +229,6 @@ MesonBuildSystem::MesonBuildSystem(BuildConfiguration *bc)
     });
 
     updateKit(kit());
-    // as specified here https://mesonbuild.com/IDE-integration.html#ide-integration
-    // meson-info.json is the last written file, which ensure that all others introspection
-    // files are ready when a modification is detected on this one.
-    m_IntroWatcher.addFile(buildConfiguration()
-                               ->buildDirectory()
-                               .pathAppended(Constants::MESON_INFO_DIR)
-                               .pathAppended(Constants::MESON_INFO),
-                           Utils::FileSystemWatcher::WatchModifiedDate);
 }
 
 MesonBuildSystem::~MesonBuildSystem()
@@ -296,6 +286,24 @@ QStringList MesonBuildSystem::configArgs(bool isSetup)
            + m_pendingConfigArgs + bc->mesonConfigArgs();
 }
 
+void MesonBuildSystem::buildDirectoryChanged()
+{
+    updateKit(kit());
+    m_IntroWatcher.clear();
+    if (buildConfiguration()->isActive())
+    {
+        // as specified here https://mesonbuild.com/IDE-integration.html#ide-integration
+        // meson-info.json is the last written file, which ensure that all others introspection
+        // files are ready when a modification is detected on this one.
+        m_IntroWatcher.addFile(buildConfiguration()
+                                   ->buildDirectory()
+                                   .pathAppended(Constants::MESON_INFO_DIR)
+                                   .pathAppended(Constants::MESON_INFO),
+                               Utils::FileSystemWatcher::WatchModifiedDate);
+    }
+    this->triggerParsing();
+}
+
 bool MesonBuildSystem::configure()
 {
     LEAVE_IF_BUSY();
@@ -337,6 +345,8 @@ bool MesonBuildSystem::wipe()
 bool MesonBuildSystem::parseProject()
 {
     QTC_ASSERT(buildConfiguration(), return false);
+    if (!buildConfiguration()->isActive()) // Never parse if not active
+        return false;
     if (!isSetup(buildConfiguration()->buildDirectory()) && settings().autorunMeson())
         return configure();
     LEAVE_IF_BUSY();
diff --git a/src/plugins/mesonprojectmanager/mesonbuildsystem.h b/src/plugins/mesonprojectmanager/mesonbuildsystem.h
index 4f749b491a3..fe5d10c43fe 100644
--- a/src/plugins/mesonprojectmanager/mesonbuildsystem.h
+++ b/src/plugins/mesonprojectmanager/mesonbuildsystem.h
@@ -42,6 +42,7 @@ private:
     bool needsSetup();
     void parsingCompleted(bool success);
     QStringList configArgs(bool isSetup);
+    void buildDirectoryChanged();
 
     ProjectExplorer::BuildSystem::ParseGuard m_parseGuard;
     MesonProjectParser m_parser;