From 99da66dbf763e9788d62e6e737507496af4278c8 Mon Sep 17 00:00:00 2001
From: Luiz Sardinha <luizin@gmail.com>
Date: Thu, 12 Feb 2026 18:40:44 +0100
Subject: [PATCH] fix: using a proper std::string to store KeyInfo buffers

---
 src/lib/deskflow/IKeyState.cpp            | 27 +++--------------------
 src/lib/deskflow/IKeyState.h              |  3 +--
 src/lib/server/InputFilter.cpp            |  4 ++--
 src/lib/server/Server.cpp                 |  4 ++--
 src/unittests/deskflow/IKeyStateTests.cpp |  2 +-
 5 files changed, 9 insertions(+), 31 deletions(-)

diff --git a/src/lib/deskflow/IKeyState.cpp b/src/lib/deskflow/IKeyState.cpp
index 553c19809..8b166c2fd 100644
--- a/src/lib/deskflow/IKeyState.cpp
+++ b/src/lib/deskflow/IKeyState.cpp
@@ -30,8 +30,6 @@ IKeyState::KeyInfo *IKeyState::KeyInfo::alloc(KeyID id, KeyModifierMask mask, Ke
   info->m_mask = mask;
   info->m_button = button;
   info->m_count = count;
-  info->m_screens = nullptr;
-  info->m_screensBuffer[0] = '\0';
   return info;
 }
 
@@ -39,43 +37,24 @@ IKeyState::KeyInfo *IKeyState::KeyInfo::alloc(
     KeyID id, KeyModifierMask mask, KeyButton button, int32_t count, const std::set<std::string> &destinations
 )
 {
-  std::string screens = join(destinations);
-  const char *buffer = screens.c_str();
-
-  // build structure
-#if SYSAPI_WIN32
-  // On windows we use malloc to avoid random test failures
-  auto *info = (KeyInfo *)malloc(sizeof(KeyInfo) + screens.size());
-#else
   auto *info = new KeyInfo();
-#endif
-
   info->m_key = id;
   info->m_mask = mask;
   info->m_button = button;
   info->m_count = count;
-  info->m_screens = info->m_screensBuffer;
-  std::copy(buffer, buffer + screens.size() + 1, info->m_screensBuffer);
+  info->m_screens = join(destinations);
   return info;
 }
 
 IKeyState::KeyInfo *IKeyState::KeyInfo::alloc(const KeyInfo &x)
 {
-  auto bufferLen = strnlen(x.m_screensBuffer, SIZE_MAX);
-
-#if SYSAPI_WIN32
-  // On windows we use malloc to avoid random test failures
-  auto info = (KeyInfo *)malloc(sizeof(KeyInfo) + bufferLen);
-#else
   auto *info = new KeyInfo();
-#endif
 
   info->m_key = x.m_key;
   info->m_mask = x.m_mask;
   info->m_button = x.m_button;
   info->m_count = x.m_count;
-  info->m_screens = x.m_screens ? info->m_screensBuffer : nullptr;
-  memcpy(info->m_screensBuffer, x.m_screensBuffer, bufferLen + 1);
+  info->m_screens = x.m_screens;
   return info;
 }
 
@@ -107,7 +86,7 @@ bool IKeyState::KeyInfo::equal(const KeyInfo *a, const KeyInfo *b)
 {
   return (
       a->m_key == b->m_key && a->m_mask == b->m_mask && a->m_button == b->m_button && a->m_count == b->m_count &&
-      strcmp(a->m_screensBuffer, b->m_screensBuffer) == 0
+      a->m_screens == b->m_screens
   );
 }
 
diff --git a/src/lib/deskflow/IKeyState.h b/src/lib/deskflow/IKeyState.h
index cad575a64..ed034fc0c 100644
--- a/src/lib/deskflow/IKeyState.h
+++ b/src/lib/deskflow/IKeyState.h
@@ -45,8 +45,7 @@ public:
     KeyModifierMask m_mask;
     KeyButton m_button;
     int32_t m_count;
-    char *m_screens;
-    char m_screensBuffer[1];
+    std::string m_screens;
   };
 
   using KeyButtonSet = std::set<KeyButton>;
diff --git a/src/lib/server/InputFilter.cpp b/src/lib/server/InputFilter.cpp
index e3e7e6da9..b9227dec0 100644
--- a/src/lib/server/InputFilter.cpp
+++ b/src/lib/server/InputFilter.cpp
@@ -469,8 +469,8 @@ std::string InputFilter::KeystrokeAction::format() const
     );
   } else {
     return deskflow::string::sprintf(
-        "%s(%s,%.*s)", type, deskflow::KeyMap::formatKey(m_keyInfo->m_key, m_keyInfo->m_mask).c_str(),
-        strnlen(m_keyInfo->m_screens + 1, SIZE_MAX) - 1, m_keyInfo->m_screens + 1
+        "%s(%s,%s)", type, deskflow::KeyMap::formatKey(m_keyInfo->m_key, m_keyInfo->m_mask).c_str(),
+        m_keyInfo->m_screens.c_str()
     );
   }
 }
diff --git a/src/lib/server/Server.cpp b/src/lib/server/Server.cpp
index fb8d676c0..3ddf06537 100644
--- a/src/lib/server/Server.cpp
+++ b/src/lib/server/Server.cpp
@@ -1219,13 +1219,13 @@ void Server::handleKeyDownEvent(const Event &event)
 {
   const auto *info = static_cast<IPlatformScreen::KeyInfo *>(event.getData());
   auto lang = AppUtil::instance().getCurrentLanguageCode();
-  onKeyDown(info->m_key, info->m_mask, info->m_button, lang, info->m_screens);
+  onKeyDown(info->m_key, info->m_mask, info->m_button, lang, info->m_screens.c_str());
 }
 
 void Server::handleKeyUpEvent(const Event &event)
 {
   auto *info = static_cast<IPlatformScreen::KeyInfo *>(event.getData());
-  onKeyUp(info->m_key, info->m_mask, info->m_button, info->m_screens);
+  onKeyUp(info->m_key, info->m_mask, info->m_button, info->m_screens.c_str());
 }
 
 void Server::handleKeyRepeatEvent(const Event &event)
diff --git a/src/unittests/deskflow/IKeyStateTests.cpp b/src/unittests/deskflow/IKeyStateTests.cpp
index d9a3e160d..d1832535d 100644
--- a/src/unittests/deskflow/IKeyStateTests.cpp
+++ b/src/unittests/deskflow/IKeyStateTests.cpp
@@ -12,7 +12,7 @@
 void IKeyStateTests::allocDestination()
 {
   auto info = IKeyState::KeyInfo::alloc(1, 2, 3, 4, {"test1", "test2"});
-  QCOMPARE(info->m_screensBuffer, ":test1:test2:");
+  QCOMPARE(info->m_screens, ":test1:test2:");
 }
 
 QTEST_MAIN(IKeyStateTests)