diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8149a85288e..3e9c0174963 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2012-11-11  Martin Jambor  <mjambor@suse.cz>
+
+	PR tree-optimization/55238
+	* ipa-cp.c (agg_pass_through_permissible_p): New function.
+	(propagate_aggs_accross_jump_function): Use it.
+	(find_aggregate_values_for_callers_subset): Likewise and relax an
+	assert.
+
 2012-11-10  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/47440
diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
index 764c931439c..85d549aad89 100644
--- a/gcc/ipa-cp.c
+++ b/gcc/ipa-cp.c
@@ -1312,6 +1312,19 @@ merge_aggregate_lattices (struct cgraph_edge *cs,
   return ret;
 }
 
+/* Determine whether there is anything to propagate FROM SRC_PLATS through a
+   pass-through JFUNC and if so, whether it has conform and conforms to the
+   rules about propagating values passed by reference.  */
+
+static bool
+agg_pass_through_permissible_p (struct ipcp_param_lattices *src_plats,
+				struct ipa_jump_func *jfunc)
+{
+  return src_plats->aggs
+    && (!src_plats->aggs_by_ref
+	|| ipa_get_jf_pass_through_agg_preserved (jfunc));
+}
+
 /* Propagate scalar values across jump function JFUNC that is associated with
    edge CS and put the values into DEST_LAT.  */
 
@@ -1333,9 +1346,7 @@ propagate_aggs_accross_jump_function (struct cgraph_edge *cs,
       struct ipcp_param_lattices *src_plats;
 
       src_plats = ipa_get_parm_lattices (caller_info, src_idx);
-      if (src_plats->aggs
-	  && (!src_plats->aggs_by_ref
-	      || ipa_get_jf_pass_through_agg_preserved (jfunc)))
+      if (agg_pass_through_permissible_p (src_plats, jfunc))
 	{
 	  /* Currently we do not produce clobber aggregate jump
 	     functions, replace with merging when we do.  */
@@ -2893,23 +2904,33 @@ find_aggregate_values_for_callers_subset (struct cgraph_node *node,
 
 	      if (caller_info->ipcp_orig_node)
 		{
-		  if (!inter)
-		    inter = agg_replacements_to_vector (cs->caller, 0);
-		  else
-		    intersect_with_agg_replacements (cs->caller, src_idx,
-						     &inter, 0);
+		  struct cgraph_node *orig_node = caller_info->ipcp_orig_node;
+		  struct ipcp_param_lattices *orig_plats;
+		  orig_plats = ipa_get_parm_lattices (IPA_NODE_REF (orig_node),
+						      src_idx);
+		  if (agg_pass_through_permissible_p (orig_plats, jfunc))
+		    {
+		      if (!inter)
+			inter = agg_replacements_to_vector (cs->caller, 0);
+		      else
+			intersect_with_agg_replacements (cs->caller, src_idx,
+							 &inter, 0);
+		    }
 		}
 	      else
 		{
 		  struct ipcp_param_lattices *src_plats;
 		  src_plats = ipa_get_parm_lattices (caller_info, src_idx);
-		  /* Currently we do not produce clobber aggregate jump
-		     functions, adjust when we do.  */
-		  gcc_checking_assert (!jfunc->agg.items);
-		  if (!inter)
-		    inter = copy_plats_to_inter (src_plats, 0);
-		  else
-		    intersect_with_plats (src_plats, &inter, 0);
+		  if (agg_pass_through_permissible_p (src_plats, jfunc))
+		    {
+		      /* Currently we do not produce clobber aggregate jump
+			 functions, adjust when we do.  */
+		      gcc_checking_assert (!jfunc->agg.items);
+		      if (!inter)
+			inter = copy_plats_to_inter (src_plats, 0);
+		      else
+			intersect_with_plats (src_plats, &inter, 0);
+		    }
 		}
 	    }
 	  else if (jfunc->type == IPA_JF_ANCESTOR
@@ -2933,7 +2954,7 @@ find_aggregate_values_for_callers_subset (struct cgraph_node *node,
 		  src_plats = ipa_get_parm_lattices (caller_info, src_idx);;
 		  /* Currently we do not produce clobber aggregate jump
 		     functions, adjust when we do.  */
-		  gcc_checking_assert (!jfunc->agg.items);
+		  gcc_checking_assert (!src_plats->aggs || !jfunc->agg.items);
 		  if (!inter)
 		    inter = copy_plats_to_inter (src_plats, delta);
 		  else
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d20dd7b38cc..d1d33896cd7 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,9 @@
-2012-11-11  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
+2012-11-11  Martin Jambor  <mjambor@suse.cz>
 
+	PR tree-optimization/55238
+	* testsuite/gcc.dg/torture/pr55238.c: New test.
+
+2012-11-11  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
 	* gcc.dg/torture/pr54920.c: Add "-fno-common" option on hppa*-*-hpux*.
 	* c-c++-common/torture/vector-subscript-1.c: Likewise.
 	* c-c++-common/torture/vector-subscript-2.c: Likewise.
diff --git a/gcc/testsuite/gcc.dg/torture/pr55238.c b/gcc/testsuite/gcc.dg/torture/pr55238.c
new file mode 100644
index 00000000000..40aafc6619c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr55238.c
@@ -0,0 +1,44 @@
+/* { dg-do compile } */
+
+typedef void * gzFile;
+typedef struct
+{
+  int mode;
+  int direct;
+  int seek;
+  int err;
+  char *msg;
+}
+gz_state;
+
+void gz_error (gz_state *state, int err, char *msg);
+
+static void
+gz_reset (gz_state *state)
+{
+  if (state->mode == 7247)
+    {
+      state->direct = 1;
+    }
+  state->seek = 0;
+  gz_error (state, 0, 0);
+}
+
+int
+gzbuffer (void *file, int size)
+{
+  gz_state *state;
+  gz_reset (state);
+}
+
+void __attribute__ ((visibility ("hidden"))) gz_error (gz_state *state, int err, char *msg)
+{
+  if (state->msg != 0)
+    {
+      if (state->err != -4)
+	foo (state->msg);
+    }
+  if (msg == 0)
+    return;
+  bar (state->msg, msg);
+}