1 files changed, 49 insertions, 0 deletions
diff --git a/windows/utils/message_box.c b/windows/utils/message_box.c
new file mode 100644
index 00000000..ae78de4a
--- /dev/null
+++ b/windows/utils/message_box.c
@@ -0,0 +1,49 @@
+/*
+ * Message box with optional context help.
+ */
+
+#include "putty.h"
+
+static HWND message_box_owner;
+
+/* Callback function to launch context help. */
+static VOID CALLBACK message_box_help_callback(LPHELPINFO lpHelpInfo)
+{
+    const char *context = NULL;
+#define CHECK_CTX(name) \
+    do { \
+        if (lpHelpInfo->dwContextId == WINHELP_CTXID_ ## name) \
+            context = WINHELP_CTX_ ## name; \
+    } while (0)
+    CHECK_CTX(errors_hostkey_absent);
+    CHECK_CTX(errors_hostkey_changed);
+    CHECK_CTX(errors_cantloadkey);
+    CHECK_CTX(option_cleanup);
+    CHECK_CTX(pgp_fingerprints);
+#undef CHECK_CTX
+    if (context)
+        launch_help(message_box_owner, context);
+}
+
+int message_box(HWND owner, LPCTSTR text, LPCTSTR caption,
+                DWORD style, DWORD helpctxid)
+{
+    MSGBOXPARAMS mbox;
+
+    /*
+     * We use MessageBoxIndirect() because it allows us to specify a
+     * callback function for the Help button.
+     */
+    mbox.cbSize = sizeof(mbox);
+    /* Assumes the globals `hinst' and `hwnd' have sensible values. */
+    mbox.hInstance = hinst;
+    mbox.hwndOwner = message_box_owner = owner;
+    mbox.lpfnMsgBoxCallback = &message_box_help_callback;
+    mbox.dwLanguageId = LANG_NEUTRAL;
+    mbox.lpszText = text;
+    mbox.lpszCaption = caption;
+    mbox.dwContextHelpId = helpctxid;
+    mbox.dwStyle = style;
+    if (helpctxid != 0 && has_help()) mbox.dwStyle |= MB_HELP;
+    return MessageBoxIndirect(&mbox);
+}