Reduce DLL hijack risk and simplify code in basic-win32 module

Dont load usp10.dll dynamically with LoadLibrary(). Just link to the
Uniscribe API directly. MinGW comes with an import library so no
problem with that either. The Uniscribe DLL is present on all versions
of Windows we care for.

2 files changed, 33 insertions, 106 deletions

diff --git a/modules/basic/Makefile.am b/modules/basic/Makefile.am
index acd0c4d4..93604c9e 100644
--- a/modules/basic/Makefile.am
+++ b/modules/basic/Makefile.am
@@ -47,7 +47,8 @@ endif
 endif
 
 pango_basic_win32_la_LDFLAGS = -module $(MODULE_LIBTOOL_OPTIONS)
-pango_basic_win32_la_LIBADD = $(pangowin32libs) -lgdi32
+pango_basic_win32_la_LIBADD = $(pangowin32libs) -lgdi32 -lusp10
+libpango_basic_win32_la_LIBADD = -lgdi32 -lusp10
 pango_basic_win32_la_SOURCES = basic-win32.c
 libpango_basic_win32_la_SOURCES = basic-win32.c
 libpango_basic_win32_la_CFLAGS = -DPANGO_MODULE_PREFIX=_pango_basic_win32
diff --git a/modules/basic/basic-win32.c b/modules/basic/basic-win32.c
index 22aafdb5..7a27d501 100644
--- a/modules/basic/basic-win32.c
+++ b/modules/basic/basic-win32.c
@@ -50,55 +50,8 @@ static gboolean pango_win32_debug = FALSE;
 
 #include <usp10.h>
 
-static gboolean have_uniscribe = FALSE;
-
 static HDC hdc;
 
-typedef HRESULT (WINAPI *pScriptGetProperties) (const SCRIPT_PROPERTIES ***,
-						int *);
-
-typedef HRESULT (WINAPI *pScriptItemize) (const WCHAR *,
-					  int,
-					  int,
-					  const SCRIPT_CONTROL *,
-					  const SCRIPT_STATE *,
-					  SCRIPT_ITEM *,
-					  int *);
-
-typedef HRESULT (WINAPI *pScriptShape) (HDC,
-					SCRIPT_CACHE *,
-					const WCHAR *,
-					int,
-					int,
-					SCRIPT_ANALYSIS *,
-					WORD *,
-					WORD *,
-					SCRIPT_VISATTR *,
-					int *);
-
-typedef HRESULT (WINAPI *pScriptPlace) (HDC,
-					SCRIPT_CACHE *,
-					const WORD *,
-					int,
-					const SCRIPT_VISATTR *,
-					SCRIPT_ANALYSIS *,
-					int *,
-					GOFFSET *,
-					ABC *);
-
-typedef HRESULT (WINAPI *pScriptFreeCache) (SCRIPT_CACHE *);
-
-typedef HRESULT (WINAPI *pScriptIsComplex) (WCHAR *,
-					    int,
-					    DWORD);
-
-static pScriptGetProperties script_get_properties;
-static pScriptItemize script_itemize;
-static pScriptShape script_shape;
-static pScriptPlace script_place;
-static pScriptFreeCache script_free_cache;
-static pScriptIsComplex script_is_complex;
-
 #ifdef BASIC_WIN32_DEBUGGING
 static const SCRIPT_PROPERTIES **scripts;
 static int nscripts;
@@ -528,8 +481,8 @@ itemize_shape_and_place (PangoFont           *font,
     g_print (G_STRLOC ": ScriptItemize: uDefaultLanguage:%04x uBidiLevel:%d\n",
 	     control.uDefaultLanguage, state.uBidiLevel);
 #endif
-  if ((*script_itemize) (wtext, wlen, G_N_ELEMENTS (items), &control, NULL,
-			 items, &nitems))
+  if (ScriptItemize (wtext, wlen, G_N_ELEMENTS (items), &control, NULL,
+		     items, &nitems))
     {
 #ifdef BASIC_WIN32_DEBUGGING
       if (pango_win32_debug)
@@ -618,14 +571,14 @@ itemize_shape_and_place (PangoFont           *font,
 	}
 
       items[item].a.fRTL = analysis->level % 2;
-      if ((*script_shape) (hdc, script_cache,
-			   wtext + items[item].iCharPos, itemlen,
-			   G_N_ELEMENTS (iglyphs),
-			   &items[item].a,
-			   iglyphs,
-			   log_clusters,
-			   visattrs,
-			   &nglyphs))
+      if (ScriptShape (hdc, script_cache,
+		       wtext + items[item].iCharPos, itemlen,
+		       G_N_ELEMENTS (iglyphs),
+		       &items[item].a,
+		       iglyphs,
+		       log_clusters,
+		       visattrs,
+		       &nglyphs))
 	{
 #ifdef BASIC_WIN32_DEBUGGING
 	  if (pango_win32_debug)
@@ -648,9 +601,9 @@ itemize_shape_and_place (PangoFont           *font,
 				 nglyphs, glyphs->log_clusters + ng,
 				 char_offset);
 
-      if ((*script_place) (hdc, script_cache, iglyphs, nglyphs,
-			   visattrs, &items[item].a,
-			   advances, offsets, &abc))
+      if (ScriptPlace (hdc, script_cache, iglyphs, nglyphs,
+		       visattrs, &items[item].a,
+		       advances, offsets, &abc))
 	{
 #ifdef BASIC_WIN32_DEBUGGING
 	  if (pango_win32_debug)
@@ -757,7 +710,7 @@ text_is_simple (const char *text,
   if (wtext == NULL)
     return TRUE;
 
-  retval = ((*script_is_complex) (wtext, wlen, SIC_COMPLEX) == S_FALSE);
+  retval = (ScriptIsComplex (wtext, wlen, SIC_COMPLEX) == S_FALSE);
 
   g_free (wtext);
 
@@ -787,8 +740,7 @@ basic_engine_shape (PangoEngineShape 	*engine,
   g_return_if_fail (length >= 0);
   g_return_if_fail (analysis != NULL);
 
-  if (have_uniscribe &&
-      !text_is_simple (text, length) &&
+  if (!text_is_simple (text, length) &&
       uniscribe_shape (font, text, length, analysis, glyphs))
     return;
 
@@ -877,33 +829,10 @@ basic_engine_shape (PangoEngineShape 	*engine,
 static void
 init_uniscribe (void)
 {
-  HMODULE usp10_dll;
-
-  have_uniscribe = FALSE;
-
-  if ((usp10_dll = LoadLibrary ("usp10.dll")) != NULL)
-    {
-      (script_get_properties = (pScriptGetProperties)
-       GetProcAddress (usp10_dll, "ScriptGetProperties")) &&
-      (script_itemize = (pScriptItemize)
-       GetProcAddress (usp10_dll, "ScriptItemize")) &&
-      (script_shape = (pScriptShape)
-       GetProcAddress (usp10_dll, "ScriptShape")) &&
-      (script_place = (pScriptPlace)
-       GetProcAddress (usp10_dll, "ScriptPlace")) &&
-      (script_free_cache = (pScriptFreeCache)
-       GetProcAddress (usp10_dll, "ScriptFreeCache")) &&
-      (script_is_complex = (pScriptIsComplex)
-       GetProcAddress (usp10_dll, "ScriptIsComplex")) &&
-      (have_uniscribe = TRUE);
-    }
-  if (have_uniscribe)
-    {
 #ifdef BASIC_WIN32_DEBUGGING
-      (*script_get_properties) (&scripts, &nscripts);
+  ScriptGetProperties (&scripts, &nscripts);
 #endif
-      hdc = pango_win32_get_dc ();
-    }
+  hdc = pango_win32_get_dc ();
 }
 
 static void
@@ -940,28 +869,25 @@ PANGO_MODULE_ENTRY(list) (PangoEngineInfo **engines,
   script_engines[0].scripts = basic_scripts;
   script_engines[0].n_scripts = G_N_ELEMENTS (basic_scripts);
 
-  if (have_uniscribe)
-    {
 #if 0
-      int i;
-      GArray *ranges = g_array_new (FALSE, FALSE, sizeof (PangoEngineRange));
+  int i;
+  GArray *ranges = g_array_new (FALSE, FALSE, sizeof (PangoEngineRange));
 
-      /* Walk through scripts supported by the Uniscribe implementation on this
-       * machine, and mark corresponding Unicode ranges.
-       */
-      for (i = 0; i < nscripts; i++)
-	{
-	}
+  /* Walk through scripts supported by the Uniscribe implementation on this
+   * machine, and mark corresponding Unicode ranges.
+   */
+  for (i = 0; i < nscripts; i++)
+    {
+    }
 
-      /* Sort range array */
-      g_array_sort (ranges, compare_range);
-      script_engines[0].ranges = ranges;
-      script_engines[0].n_ranges = ranges->len;
+  /* Sort range array */
+  g_array_sort (ranges, compare_range);
+  script_engines[0].ranges = ranges;
+  script_engines[0].n_ranges = ranges->len;
 #else
-      script_engines[0].scripts = uniscribe_scripts;
-      script_engines[0].n_scripts = G_N_ELEMENTS (uniscribe_scripts);
+  script_engines[0].scripts = uniscribe_scripts;
+  script_engines[0].n_scripts = G_N_ELEMENTS (uniscribe_scripts);
 #endif
-    }
 
   *engines = script_engines;
   *n_engines = G_N_ELEMENTS (script_engines);