From e57692e4f5ff9c187226a89fdde9baa5292dee7a Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 9 Apr 2024 21:19:25 +0530
Subject: [PATCH] Possibly fix #7327

---
 glfw/cocoa_platform.h |  2 +-
 glfw/cocoa_window.m   | 22 +++++++++++++---------
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/glfw/cocoa_platform.h b/glfw/cocoa_platform.h
index 58f7fd6cc..cead7c545 100644
--- a/glfw/cocoa_platform.h
+++ b/glfw/cocoa_platform.h
@@ -184,7 +184,7 @@ typedef struct _GLFWlibraryNS
     id                  nibObjects;
 
     char                keyName[64];
-    char                text[256];
+    char                text[512];
     CGPoint             cascadePoint;
     // Where to place the cursor when re-enabled
     double              restoreCursorPosX, restoreCursorPosY;
diff --git a/glfw/cocoa_window.m b/glfw/cocoa_window.m
index 1be408816..003668b63 100644
--- a/glfw/cocoa_window.m
+++ b/glfw/cocoa_window.m
@@ -1541,16 +1541,20 @@ void _glfwPlatformUpdateIMEState(_GLFWwindow *w, const GLFWIMEUpdateEvent *ev) {
         }
     }
     // insertText can be called multiple times for a single key event
-    char *s = _glfw.ns.text + strnlen(_glfw.ns.text, sizeof(_glfw.ns.text));
-    snprintf(s, sizeof(_glfw.ns.text) - (s - _glfw.ns.text), "%s", utf8);
-    _glfw.ns.text[sizeof(_glfw.ns.text) - 1] = 0;
-    if ((!in_key_handler || in_key_handler == 2) && _glfw.ns.text[0]) {
-        if (!is_ascii_control_char(_glfw.ns.text[0])) {
-            debug_key("Sending text to kitty from insertText called from %s: %s\n", in_key_handler ? "flagsChanged" : "event loop", _glfw.ns.text);
-            GLFWkeyevent glfw_keyevent = {.text=_glfw.ns.text, .ime_state=GLFW_IME_COMMIT_TEXT};
-            _glfwInputKeyboard(window, &glfw_keyevent);
+    size_t existing_length = strnlen(_glfw.ns.text, sizeof(_glfw.ns.text));
+    size_t required_length = strlen(utf8) + 1;
+    size_t available_length = sizeof(_glfw.ns.text) - existing_length;
+    if (available_length >= required_length) {
+        memcpy(_glfw.ns.text + existing_length, utf8, required_length); // copies the null terminator from utf8 as well
+        _glfw.ns.text[sizeof(_glfw.ns.text) - 1] = 0;
+        if ((!in_key_handler || in_key_handler == 2) && _glfw.ns.text[0]) {
+            if (!is_ascii_control_char(_glfw.ns.text[0])) {
+                debug_key("Sending text to kitty from insertText called from %s: %s\n", in_key_handler ? "flagsChanged" : "event loop", _glfw.ns.text);
+                GLFWkeyevent glfw_keyevent = {.text=_glfw.ns.text, .ime_state=GLFW_IME_COMMIT_TEXT};
+                _glfwInputKeyboard(window, &glfw_keyevent);
+            }
+            _glfw.ns.text[0] = 0;
         }
-        _glfw.ns.text[0] = 0;
     }
 }