diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f2db22542c6..de7420ff09a 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2006-06-21  Jakub Jelinek  <jakub@redhat.com>
+
+	* varasm.c (mergeable_string_section): Check for embedded NULs and
+	NUL termination in the first int_size_in_bytes (TREE_TYPE (decl))
+	rather than TREE_STRING_LENGTH bytes.
+
 2006-06-21  Richard Guenther  <rguenther@suse.de>
 
 	* ggc-page.c (extra_order_size_table): Add var_ann_d,
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 461e04c811f..84dd8898d59 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2006-06-21  Jakub Jelinek  <jakub@redhat.com>
+
+	* gcc.dg/merge-all-constants-1.c: New test.
+
 2006-06-20  Janis Johnson  <janis187@us.ibm.com>
 
 	PR c++/28113
diff --git a/gcc/testsuite/gcc.dg/merge-all-constants-1.c b/gcc/testsuite/gcc.dg/merge-all-constants-1.c
new file mode 100644
index 00000000000..5c9cd06e925
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/merge-all-constants-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-w -O2 -fmerge-all-constants" } */
+
+const char str1[36] = "0123456789abcdefghijklmnopqrstuvwxyz";
+const char str2[38] = "0123456789abcdefghijklmnopqrstuvwxyz";
+const char str3[10] = "0123456789abcdefghijklmnopqrstuvwxyz";
+
+/* { dg-final { scan-assembler-not "\.rodata\.str" } } */
diff --git a/gcc/varasm.c b/gcc/varasm.c
index 71158ba860b..e5abd3e2d97 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -655,16 +655,20 @@ mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
 			  unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED,
 			  unsigned int flags ATTRIBUTE_UNUSED)
 {
+  HOST_WIDE_INT len;
+
   if (HAVE_GAS_SHF_MERGE && flag_merge_constants
       && TREE_CODE (decl) == STRING_CST
       && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
       && align <= 256
-      && TREE_STRING_LENGTH (decl) >= int_size_in_bytes (TREE_TYPE (decl)))
+      && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0
+      && TREE_STRING_LENGTH (decl) >= len)
     {
       enum machine_mode mode;
       unsigned int modesize;
       const char *str;
-      int i, j, len, unit;
+      HOST_WIDE_INT i;
+      int j, unit;
       char name[30];
 
       mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl)));
@@ -676,7 +680,6 @@ mergeable_string_section (tree decl ATTRIBUTE_UNUSED,
 	    align = modesize;
 
 	  str = TREE_STRING_POINTER (decl);
-	  len = TREE_STRING_LENGTH (decl);
 	  unit = GET_MODE_SIZE (mode);
 
 	  /* Check for embedded NUL characters.  */