diff --git a/ChangeLog b/ChangeLog
index c48442d988..fde9f03f76 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2009-08-23  Ulrich Drepper  <drepper@redhat.com>
 
+	* stdio-common/printf_fp.c: ISO C expects to print the sign of NaN
+	as well.
+	* stdio-common/printf_fphex.c: Likewise.
+	* stdio-common/tstdiomisc.c: Add more tests.
+
 	* locale/locale.h: Include xlocale.h and the thread-local locale
 	declarations for XPG7, not XPG6.
 
diff --git a/stdio-common/printf_fp.c b/stdio-common/printf_fp.c
index 43c43c2039..cd3ada6441 100644
--- a/stdio-common/printf_fp.c
+++ b/stdio-common/printf_fp.c
@@ -28,6 +28,7 @@
 #include <float.h>
 #include <gmp-mparam.h>
 #include <gmp.h>
+#include <ieee754.h>
 #include <stdlib/gmp-impl.h>
 #include <stdlib/longlong.h>
 #include <stdlib/fpioconst.h>
@@ -335,6 +336,8 @@ ___printf_fp (FILE *fp,
       /* Check for special values: not a number or infinity.  */
       if (__isnanl (fpnum.ldbl))
 	{
+	  union ieee854_long_double u = { .d = fpnum.ldbl };
+	  is_neg = u.ieee.negative != 0;
 	  if (isupper (info->spec))
 	    {
 	      special = "NAN";
@@ -345,10 +348,10 @@ ___printf_fp (FILE *fp,
 		special = "nan";
 		wspecial = L"nan";
 	      }
-	  is_neg = 0;
 	}
       else if (__isinfl (fpnum.ldbl))
 	{
+	  is_neg = fpnum.ldbl < 0;
 	  if (isupper (info->spec))
 	    {
 	      special = "INF";
@@ -359,7 +362,6 @@ ___printf_fp (FILE *fp,
 	      special = "inf";
 	      wspecial = L"inf";
 	    }
-	  is_neg = fpnum.ldbl < 0;
 	}
       else
 	{
@@ -379,7 +381,8 @@ ___printf_fp (FILE *fp,
       /* Check for special values: not a number or infinity.  */
       if (__isnan (fpnum.dbl))
 	{
-	  is_neg = 0;
+	  union ieee754_double u = { .d = fpnum.dbl };
+	  is_neg = u.ieee.negative != 0;
 	  if (isupper (info->spec))
 	    {
 	      special = "NAN";
diff --git a/stdio-common/printf_fphex.c b/stdio-common/printf_fphex.c
index 4e30d94c61..551c873c5e 100644
--- a/stdio-common/printf_fphex.c
+++ b/stdio-common/printf_fphex.c
@@ -172,6 +172,7 @@ __printf_fphex (FILE *fp,
       /* Check for special values: not a number or infinity.  */
       if (__isnanl (fpnum.ldbl.d))
 	{
+	  negative = fpnum.ldbl.ieee.negative != 0;
 	  if (isupper (info->spec))
 	    {
 	      special = "NAN";
@@ -182,7 +183,6 @@ __printf_fphex (FILE *fp,
 	      special = "nan";
 	      wspecial = L"nan";
 	    }
-	  negative = 0;
 	}
       else
 	{
@@ -211,6 +211,7 @@ __printf_fphex (FILE *fp,
       /* Check for special values: not a number or infinity.  */
       if (__isnan (fpnum.dbl.d))
 	{
+	  negative = fpnum.dbl.ieee.negative != 0;
 	  if (isupper (info->spec))
 	    {
 	      special = "NAN";
@@ -221,7 +222,6 @@ __printf_fphex (FILE *fp,
 	      special = "nan";
 	      wspecial = L"nan";
 	    }
-	  negative = 0;
 	}
       else
 	{
diff --git a/stdio-common/tstdiomisc.c b/stdio-common/tstdiomisc.c
index db038fa2b0..c1c68955bd 100644
--- a/stdio-common/tstdiomisc.c
+++ b/stdio-common/tstdiomisc.c
@@ -47,33 +47,129 @@ t2 (void)
 }
 
 volatile double nanval;
+volatile double infval;
+volatile long double lnanval;
+volatile long double linfval;
 
 
 static int
 F (void)
 {
-  char buf[20];
-  wchar_t wbuf[10];
+  char buf[80];
+  wchar_t wbuf[40];
   int result;
 
   nanval = NAN;
 
-  snprintf (buf, sizeof buf, "%f %F", nanval, nanval);
-  result = strcmp (buf, "nan NAN") != 0;
-  printf ("expected \"nan NAN\", got \"%s\"\n", buf);
+  snprintf (buf, sizeof buf, "%a %A %e %E %f %F %g %G",
+	    nanval, nanval, nanval, nanval, nanval, nanval, nanval, nanval);
+  result = strcmp (buf, "nan NAN nan NAN nan NAN nan NAN") != 0;
+  printf ("expected \"nan NAN nan NAN nan NAN nan NAN\", got \"%s\"\n", buf);
 
-  snprintf (buf, sizeof buf, "%f %F", DBL_MAX * DBL_MAX, DBL_MAX * DBL_MAX);
-  result |= strcmp (buf, "inf INF") != 0;
-  printf ("expected \"inf INF\", got \"%s\"\n", buf);
+  snprintf (buf, sizeof buf, "%a %A %e %E %f %F %g %G",
+	    -nanval, -nanval, -nanval, -nanval,
+	    -nanval, -nanval, -nanval, -nanval);
+  result = strcmp (buf, "-nan -NAN -nan -NAN -nan -NAN -nan -NAN") != 0;
+  printf ("expected \"-nan -NAN -nan -NAN -nan -NAN -nan -NAN\", got \"%s\"\n",
+	  buf);
 
-  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]), L"%f %F", nanval, nanval);
-  result |= wcscmp (wbuf, L"nan NAN") != 0;
-  printf ("expected L\"nan NAN\", got L\"%S\"\n", wbuf);
+  infval = DBL_MAX * DBL_MAX;
 
-  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]), L"%f %F",
-	    DBL_MAX * DBL_MAX, DBL_MAX * DBL_MAX);
-  result |= wcscmp (wbuf, L"inf INF") != 0;
-  printf ("expected L\"inf INF\", got L\"%S\"\n", wbuf);
+  snprintf (buf, sizeof buf, "%a %A %e %E %f %F %g %G",
+	    infval, infval, infval, infval, infval, infval, infval, infval);
+  result |= strcmp (buf, "inf INF inf INF inf INF inf INF") != 0;
+  printf ("expected \"inf INF inf INF inf INF inf INF\", got \"%s\"\n", buf);
+
+  snprintf (buf, sizeof buf, "%a %A %e %E %f %F %g %G",
+	    -infval, -infval, -infval, -infval,
+	    -infval, -infval, -infval, -infval);
+  result |= strcmp (buf, "-inf -INF -inf -INF -inf -INF -inf -INF") != 0;
+  printf ("expected \"-inf -INF -inf -INF -inf -INF -inf -INF\", got \"%s\"\n",
+	  buf);
+
+  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]), L"%a %A %e %E %f %F %g %G",
+	    nanval, nanval, nanval, nanval, nanval, nanval, nanval, nanval);
+  result |= wcscmp (wbuf, L"nan NAN nan NAN nan NAN nan NAN") != 0;
+  printf ("expected L\"nan NAN nan NAN nan NAN nan NAN\", got L\"%S\"\n", wbuf);
+
+  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]), L"%a %A %e %E %f %F %g %G",
+	    -nanval, -nanval, -nanval, -nanval,
+	    -nanval, -nanval, -nanval, -nanval);
+  result |= wcscmp (wbuf, L"-nan -NAN -nan -NAN -nan -NAN -nan -NAN") != 0;
+  printf ("expected L\"-nan -NAN -nan -NAN -nan -NAN -nan -NAN\", got L\"%S\"\n",
+	  wbuf);
+
+  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]), L"%a %A %e %E %f %F %g %G",
+	    infval, infval, infval, infval, infval, infval, infval, infval);
+  result |= wcscmp (wbuf, L"inf INF inf INF inf INF inf INF") != 0;
+  printf ("expected L\"inf INF inf INF inf INF inf INF\", got L\"%S\"\n", wbuf);
+
+  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]), L"%a %A %e %E %f %F %g %G",
+	    -infval, -infval, -infval, -infval,
+	    -infval, -infval, -infval, -infval);
+  result |= wcscmp (wbuf, L"-inf -INF -inf -INF -inf -INF -inf -INF") != 0;
+  printf ("expected L\"-inf -INF -inf -INF -inf -INF -inf -INF\", got L\"%S\"\n",
+	  wbuf);
+
+  lnanval = NAN;
+
+  snprintf (buf, sizeof buf, "%La %LA %Le %LE %Lf %LF %Lg %LG",
+	    lnanval, lnanval, lnanval, lnanval,
+	    lnanval, lnanval, lnanval, lnanval);
+  result = strcmp (buf, "nan NAN nan NAN nan NAN nan NAN") != 0;
+  printf ("expected \"nan NAN nan NAN nan NAN nan NAN\", got \"%s\"\n", buf);
+
+  snprintf (buf, sizeof buf, "%La %LA %Le %LE %Lf %LF %Lg %LG",
+	    -lnanval, -lnanval, -lnanval, -lnanval,
+	    -lnanval, -lnanval, -lnanval, -lnanval);
+  result = strcmp (buf, "-nan -NAN -nan -NAN -nan -NAN -nan -NAN") != 0;
+  printf ("expected \"-nan -NAN -nan -NAN -nan -NAN -nan -NAN\", got \"%s\"\n",
+	  buf);
+
+  linfval = LDBL_MAX * LDBL_MAX;
+
+  snprintf (buf, sizeof buf, "%La %LA %Le %LE %Lf %LF %Lg %LG",
+	    linfval, linfval, linfval, linfval,
+	    linfval, linfval, linfval, linfval);
+  result |= strcmp (buf, "inf INF inf INF inf INF inf INF") != 0;
+  printf ("expected \"inf INF inf INF inf INF inf INF\", got \"%s\"\n", buf);
+
+  snprintf (buf, sizeof buf, "%La %LA %Le %LE %Lf %LF %Lg %LG",
+	    -linfval, -linfval, -linfval, -linfval,
+	    -linfval, -linfval, -linfval, -linfval);
+  result |= strcmp (buf, "-inf -INF -inf -INF -inf -INF -inf -INF") != 0;
+  printf ("expected \"-inf -INF -inf -INF -inf -INF -inf -INF\", got \"%s\"\n",
+	  buf);
+
+  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]),
+	    L"%La %LA %Le %LE %Lf %LF %Lg %LG",
+	    lnanval, lnanval, lnanval, lnanval,
+	    lnanval, lnanval, lnanval, lnanval);
+  result |= wcscmp (wbuf, L"nan NAN nan NAN nan NAN nan NAN") != 0;
+  printf ("expected L\"nan NAN nan NAN nan NAN nan NAN\", got L\"%S\"\n", wbuf);
+
+  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]),
+	    L"%La %LA %Le %LE %Lf %LF %Lg %LG",
+	    -lnanval, -lnanval, -lnanval, -lnanval,
+	    -lnanval, -lnanval, -lnanval, -lnanval);
+  result |= wcscmp (wbuf, L"-nan -NAN -nan -NAN -nan -NAN -nan -NAN") != 0;
+  printf ("expected L\"-nan -NAN -nan -NAN -nan -NAN -nan -NAN\", got L\"%S\"\n",
+	  wbuf);
+
+  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]),
+	    L"%La %LA %Le %LE %Lf %LF %Lg %LG",
+	    linfval, linfval, linfval, linfval,
+	    linfval, linfval, linfval, linfval);
+  result |= wcscmp (wbuf, L"inf INF inf INF inf INF inf INF") != 0;
+  printf ("expected L\"inf INF inf INF inf INF inf INF\", got L\"%S\"\n", wbuf);
+
+  swprintf (wbuf, sizeof wbuf / sizeof (wbuf[0]),
+	    L"%La %LA %Le %LE %Lf %LF %Lg %LG",
+	    -linfval, -linfval, -linfval, -linfval,
+	    -linfval, -linfval, -linfval, -linfval);
+  result |= wcscmp (wbuf, L"-inf -INF -inf -INF -inf -INF -inf -INF") != 0;
+  printf ("expected L\"-inf -INF -inf -INF -inf -INF -inf -INF\", got L\"%S\"\n",
+	  wbuf);
 
   return result;
 }