gconv: Consistently mangle NULL function pointers [BZ #22025]

Not mangling NULL pointers is not safe because with very low
probability, a non-NULL function pointer can turn into a NULL pointer
after mangling.

3 files changed, 23 insertions, 35 deletions

diff --git a/iconv/gconv_cache.c b/iconv/gconv_cache.c
index d6a47de..7d2751a 100644
--- a/iconv/gconv_cache.c
+++ b/iconv/gconv_cache.c
@@ -207,17 +207,16 @@ find_module (const char *directory, const char *filename,
       result->__data = NULL;
 
       /* Call the init function.  */
-      if (result->__init_fct != NULL)
-	{
-	  __gconv_init_fct init_fct = result->__init_fct;
+      __gconv_init_fct init_fct = result->__init_fct;
 #ifdef PTR_DEMANGLE
-	  PTR_DEMANGLE (init_fct);
+      PTR_DEMANGLE (init_fct);
 #endif
+      if (init_fct != NULL)
+	{
 	  status = DL_CALL_FCT (init_fct, (result));
 
 #ifdef PTR_MANGLE
-	  if (result->__btowc_fct != NULL)
-	    PTR_MANGLE (result->__btowc_fct);
+	  PTR_MANGLE (result->__btowc_fct);
 #endif
 	}
     }
diff --git a/iconv/gconv_db.c b/iconv/gconv_db.c
index 7893fad..b748467 100644
--- a/iconv/gconv_db.c
+++ b/iconv/gconv_db.c
@@ -179,16 +179,15 @@ free_derivation (void *p)
   size_t cnt;
 
   for (cnt = 0; cnt < deriv->nsteps; ++cnt)
-    if (deriv->steps[cnt].__counter > 0
-	&& deriv->steps[cnt].__end_fct != NULL)
+    if ((deriv->steps[cnt].__counter > 0)
+	&& (deriv->steps[cnt].__shlib_handle != NULL))
       {
-	assert (deriv->steps[cnt].__shlib_handle != NULL);
-
 	__gconv_end_fct end_fct = deriv->steps[cnt].__end_fct;
 #ifdef PTR_DEMANGLE
 	PTR_DEMANGLE (end_fct);
 #endif
-	DL_CALL_FCT (end_fct, (&deriv->steps[cnt]));
+	if (end_fct != NULL)
+	  DL_CALL_FCT (end_fct, (&deriv->steps[cnt]));
       }
 
   /* Free the name strings.  */
@@ -212,16 +211,12 @@ __gconv_release_step (struct __gconv_step *step)
   if (step->__shlib_handle != NULL && --step->__counter == 0)
     {
       /* Call the destructor.  */
-      if (step->__end_fct != NULL)
-	{
-	  assert (step->__shlib_handle != NULL);
-
-	  __gconv_end_fct end_fct = step->__end_fct;
+	__gconv_end_fct end_fct = step->__end_fct;
 #ifdef PTR_DEMANGLE
-	  PTR_DEMANGLE (end_fct);
+	PTR_DEMANGLE (end_fct);
 #endif
-	  DL_CALL_FCT (end_fct, (step));
-	}
+      if (end_fct != NULL)
+	DL_CALL_FCT (end_fct, (step));
 
 #ifndef STATIC_GCONV
       /* Release the loaded module.  */
@@ -313,13 +308,11 @@ gen_steps (struct derivation_step *best, const char *toset,
 
 	      /* Call the init function.  */
 	      __gconv_init_fct init_fct = result[step_cnt].__init_fct;
-	      if (init_fct != NULL)
-		{
-		  assert (result[step_cnt].__shlib_handle != NULL);
-
 # ifdef PTR_DEMANGLE
-		  PTR_DEMANGLE (init_fct);
+	      PTR_DEMANGLE (init_fct);
 # endif
+	      if (init_fct != NULL)
+		{
 		  status = DL_CALL_FCT (init_fct, (&result[step_cnt]));
 
 		  if (__builtin_expect (status, __GCONV_OK) != __GCONV_OK)
@@ -332,8 +325,7 @@ gen_steps (struct derivation_step *best, const char *toset,
 		    }
 
 # ifdef PTR_MANGLE
-		  if (result[step_cnt].__btowc_fct != NULL)
-		    PTR_MANGLE (result[step_cnt].__btowc_fct);
+		  PTR_MANGLE (result[step_cnt].__btowc_fct);
 # endif
 		}
 	    }
@@ -415,16 +407,15 @@ increment_counter (struct __gconv_step *steps, size_t nsteps)
 
 	  /* Call the init function.  */
 	  __gconv_init_fct init_fct = step->__init_fct;
-	  if (init_fct != NULL)
-	    {
 #ifdef PTR_DEMANGLE
-	      PTR_DEMANGLE (init_fct);
+	  PTR_DEMANGLE (init_fct);
 #endif
+	  if (init_fct != NULL)
+	    {
 	      DL_CALL_FCT (init_fct, (step));
 
 #ifdef PTR_MANGLE
-	      if (step->__btowc_fct != NULL)
-		PTR_MANGLE (step->__btowc_fct);
+	      PTR_MANGLE (step->__btowc_fct);
 #endif
 	    }
 	}
diff --git a/iconv/gconv_dl.c b/iconv/gconv_dl.c
index 2418362..d7dbba9 100644
--- a/iconv/gconv_dl.c
+++ b/iconv/gconv_dl.c
@@ -131,10 +131,8 @@ __gconv_find_shlib (const char *name)
 
 #ifdef PTR_MANGLE
 		  PTR_MANGLE (found->fct);
-		  if (found->init_fct != NULL)
-		    PTR_MANGLE (found->init_fct);
-		  if (found->end_fct !=  NULL)
-		    PTR_MANGLE (found->end_fct);
+		  PTR_MANGLE (found->init_fct);
+		  PTR_MANGLE (found->end_fct);
 #endif
 
 		  /* We have succeeded in loading the shared object.  */