From e0732151aa27aea76f04558f6414bd95510621df Mon Sep 17 00:00:00 2001
From: Christoph Reiter <reiter.christoph@gmail.com>
Date: Fri, 16 Oct 2020 14:44:15 +0200
Subject: [PATCH] 2.50-gmodule-cygwin (rebased)

---
 gmodule/gmodule-win32.c | 72 +++++++++++++++++++++++++++++++++++------
 1 file changed, 63 insertions(+), 9 deletions(-)

diff --git a/gmodule/gmodule-win32.c b/gmodule/gmodule-win32.c
index 2aea8bae9..4ee741cce 100644
--- a/gmodule/gmodule-win32.c
+++ b/gmodule/gmodule-win32.c
@@ -37,7 +37,20 @@
 
 #ifdef G_WITH_CYGWIN
 #include <sys/cygwin.h>
-#endif
+#include <dlfcn.h>
+
+static gchar*
+fetch_dlerror (gboolean replace_null)
+{
+  gchar *msg = dlerror ();
+
+  if (!msg && replace_null)
+    return "unknown dl-error";
+
+  return msg;
+}
+
+#else
 
 static void G_GNUC_PRINTF (1, 2)
 set_error (const gchar *format,
@@ -62,22 +75,26 @@ set_error (const gchar *format,
   g_free (error);
 }
 
+#endif /* G_WITH_CYGWIN */
+
 /* --- functions --- */
 static gpointer
 _g_module_open (const gchar *file_name,
 		gboolean     bind_lazy,
 		gboolean     bind_local)
 {
+#ifdef G_WITH_CYGWIN
+  gpointer handle;
+
+  handle = dlopen (file_name,
+          (bind_local ? RTLD_LOCAL : RTLD_GLOBAL) | (bind_lazy ? RTLD_LAZY : RTLD_NOW));
+  if (!handle)
+    g_module_set_error (fetch_dlerror (TRUE));
+#else
   HINSTANCE handle;
   wchar_t *wfilename;
   DWORD old_mode;
   BOOL success;
-#ifdef G_WITH_CYGWIN
-  gchar tmp[MAX_PATH];
-
-  cygwin_conv_to_win32_path(file_name, tmp);
-  file_name = tmp;
-#endif
   wfilename = g_utf8_to_utf16 (file_name, -1, NULL, NULL, NULL);
 
   /* suppress error dialog */
@@ -99,25 +116,43 @@ _g_module_open (const gchar *file_name,
       
   if (!handle)
     set_error ("'%s': ", file_name);
+#endif
 
   return handle;
 }
 
+#ifndef G_WITH_CYGWIN
 static gint dummy;
 static gpointer null_module_handle = &dummy;
+#endif
   
 static gpointer
 _g_module_self (void)
 {
+#ifdef G_WITH_CYGWIN
+  gpointer handle;
+
+  handle = dlopen (NULL, RTLD_GLOBAL | RTLD_LAZY);
+  if (!handle)
+    g_module_set_error (fetch_dlerror (TRUE));
+
+  return handle;
+#else
   return null_module_handle;
+#endif
 }
 
 static void
 _g_module_close (gpointer handle)
 {
+#ifdef G_WITH_CYGWIN
+  if (dlclose (handle) != 0)
+    g_module_set_error (fetch_dlerror (TRUE));
+#else
   if (handle != null_module_handle)
     if (!FreeLibrary (handle))
       set_error ("");
+#endif
 }
 
 static gpointer
@@ -152,8 +187,19 @@ find_in_any_module_using_toolhelp (const gchar *symbol_name)
   if (Module32First (snapshot, &me32))
     {
       do {
-	if ((p = GetProcAddress (me32.hModule, symbol_name)) != NULL)
-	  break;
+	if ((p = GetProcAddress (me32.hModule, symbol_name)) != NULL) {
+#ifdef G_WITH_CYGWIN
+	  /* if symbol is found in another module, we probably do not want it */
+	  ssize_t size = cygwin_conv_path (CCP_WIN_A_TO_POSIX, me32.szExePath, NULL, 0);
+	  char *posix = (char *) alloca (size);
+	  cygwin_conv_path (CCP_WIN_A_TO_POSIX, me32.szExePath, posix, size);
+	  if (g_strstr_len (posix, size, "/usr/lib")
+	      || g_strstr_len (posix, size, "/usr/local/lib"))
+	    p = NULL;
+	  else
+#endif
+	    break;
+	  }
       } while (Module32Next (snapshot, &me32));
     }
 
@@ -180,6 +226,13 @@ _g_module_symbol (gpointer     handle,
 {
   gpointer p;
   
+#ifdef G_WITH_CYGWIN
+  p = dlsym (handle, symbol_name);
+  if (!p)
+    p = find_in_any_module (symbol_name);
+  if (!p)
+    g_module_set_error (fetch_dlerror (FALSE));
+#else
   if (handle == null_module_handle)
     {
       if ((p = GetProcAddress (GetModuleHandle (NULL), symbol_name)) == NULL)
@@ -190,6 +243,7 @@ _g_module_symbol (gpointer     handle,
 
   if (!p)
     set_error ("");
+#endif
 
   return p;
 }
-- 
2.28.0