Handle git cancellation when closing

Tidies up a few places where we need to hold the mutex and early exit
from loops if we are quitting

Fixes https://gitlab.com/kicad/code/kicad/-/issues/21849

(cherry picked from commit fd2ddf60b7)

common/git/kicad_git_common.cpp

@@ -258,7 +258,7 @@ std::pair<std::set<wxString>,std::set<wxString>> KIGIT_COMMON::GetDifferentFiles
         std::set<wxString> modified_set;
         git_revwalk* walker = nullptr;
 
-        if( !m_repo || !from_oid )
+        if( !m_repo || !from_oid || IsCancelled() )
             return modified_set;
 
         if( git_revwalk_new( &walker, m_repo ) != GIT_OK )
@@ -286,6 +286,10 @@ std::pair<std::set<wxString>,std::set<wxString>> KIGIT_COMMON::GetDifferentFiles
         // iterate over all local commits not in remote
         while( git_revwalk_next( &oid, walker ) == GIT_OK )
         {
+            // Check for cancellation to allow early exit during shutdown
+            if( IsCancelled() )
+                return modified_set;
+
             if( git_commit_lookup( &commit, m_repo, &oid ) != GIT_OK )
             {
                 wxLogTrace( traceGit, "Failed to lookup commit: %s", KIGIT_COMMON::GetLastGitError() );
@@ -371,7 +375,7 @@ std::pair<std::set<wxString>,std::set<wxString>> KIGIT_COMMON::GetDifferentFiles
 
     std::pair<std::set<wxString>,std::set<wxString>> modified_files;
 
-    if( !m_repo )
+    if( !m_repo || IsCancelled() )
         return modified_files;
 
     git_reference* head = nullptr;

common/git/kicad_git_common.h

@@ -26,6 +26,7 @@
 
 #include <git/kicad_git_errors.h>
 
+#include <atomic>
 #include <git2.h>
 #include <mutex>
 #include <set>
@@ -138,6 +139,12 @@ public:
 
     int HandleSSHAgentAuthentication( git_cred** aOut, const wxString& aUsername );
 
+    bool IsCancelled() const { return m_cancel.load(); }
+
+    void SetCancelled( bool aCancel ) { m_cancel.store( aCancel ); }
+
+    std::mutex& GetMutex() { return m_gitActionMutex; }
+
     static wxString GetLastGitError()
     {
         const git_error* error = git_error_last();
@@ -174,6 +181,8 @@ private:
     int m_nextPublicKey;
     bool m_secretFetched;
 
+    std::atomic<bool> m_cancel{ false };
+
     // Create a dummy flag to tell if we have tested ssh agent credentials separately
     // from the ssh key credentials
     static const unsigned KIGIT_CREDENTIAL_SSH_AGENT = 1 << sizeof( m_testedTypes - 1 );

kicad/project_tree_pane.cpp

@@ -2133,6 +2133,21 @@ void PROJECT_TREE_PANE::updateGitStatusIconMap()
         return;
     }
 
+    std::unique_lock<std::mutex> gitLock( m_TreeProject->GitCommon()->GetMutex(),
+                                          std::try_to_lock );
+
+    if( !gitLock.owns_lock() )
+    {
+        wxLogTrace( traceGit, wxS( "updateGitStatusIconMap: Failed to acquire git action mutex" ) );
+        return;
+    }
+
+    if( m_TreeProject->GitCommon()->IsCancelled() )
+    {
+        wxLogTrace( traceGit, wxS( "updateGitStatusIconMap: Cancelled" ) );
+        return;
+    }
+
     // Get Current Branch
     wxFileName         rootFilename( Prj().GetProjectFullName() );
     wxString           repoWorkDir( git_repository_workdir( repo ) );
@@ -2726,13 +2741,22 @@ void PROJECT_TREE_PANE::onGitSyncTimer( wxTimerEvent& aEvent )
                     return;
                 }
 
+                if( gitCommon->IsCancelled() )
+                {
+                    wxLogTrace( traceGit, "onGitSyncTimer: Cancelled" );
+                    return;
+                }
+
                 GIT_PULL_HANDLER handler( gitCommon );
                 handler.PerformFetch();
 
-                CallAfter( [this]()
+                if( !gitCommon->IsCancelled() )
                 {
-                    gitStatusTimerHandler();
-                } );
+                    CallAfter( [this]()
+                    {
+                        gitStatusTimerHandler();
+                    } );
+                }
             } );
 
     if( gitSettings.updatInterval > 0 )
@@ -2746,6 +2770,11 @@ void PROJECT_TREE_PANE::onGitSyncTimer( wxTimerEvent& aEvent )
 
 void PROJECT_TREE_PANE::gitStatusTimerHandler()
 {
+    KIGIT_COMMON* gitCommon = m_TreeProject ? m_TreeProject->GitCommon() : nullptr;
+
+    if( !gitCommon || gitCommon->IsCancelled() )
+        return;
+
     updateTreeCache();
     thread_pool& tp = GetKiCadThreadPool();