[PATCH v2] msvcrt: Make the cosh/sinh/tanh functions NAN preserving

[Martin Storsjo]

When a NAN is fed as input, return it as-is without mangling
it through the calculation (which e.g. loses the sign of the
input value).

This fixes a regression in a testcase of mine, after switching
to the internal implementation of these functions.

Signed-off-by: Martin Storsjo <martin at martin.st>
---
As these routines are imported from musl, I guess I should try to
upstream the same fix to them too.

v2: Keep the math error reporting for msvcrt < 140 in tanh.
---
 dlls/msvcrt/math.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/dlls/msvcrt/math.c b/dlls/msvcrt/math.c
index ecf5fdce4d8..9b69f6bea56 100644
--- a/dlls/msvcrt/math.c
+++ b/dlls/msvcrt/math.c
@@ -1139,6 +1139,9 @@ float CDECL coshf( float x )
     UINT32 ui = *(UINT32*)&x;
     float t;
 
+    if (isnan(x))
+        return x;
+
     /* |x| */
     ui &= 0x7fffffff;
     x = *(float*)&ui;
@@ -1676,6 +1679,9 @@ float CDECL sinhf( float x )
     UINT32 ui = *(UINT32*)&x;
     float t, h, absx;
 
+    if (isnan(x))
+        return x;
+
     h = 0.5;
     if (ui >> 31)
         h = -h;
@@ -1885,9 +1891,11 @@ float CDECL tanhf( float x )
     if (ui > 0x3f0c9f54) {
         /* |x| > log(3)/2 ~= 0.5493 or nan */
         if (ui > 0x41200000) {
-#if _MSVCR_VER < 140
             if (isnan(x))
+#if _MSVCR_VER < 140
                 return math_error(_DOMAIN, "tanhf", x, 0, x);
+#else
+                return x;
 #endif
             /* |x| > 10 */
             fp_barrierf(x + 0x1p120f);
@@ -2769,6 +2777,9 @@ double CDECL cosh( double x )
     UINT32 w;
     double t;
 
+    if (isnan(x))
+        return x;
+
     /* |x| */
     ux &= (uint64_t)-1 / 2;
     x = *(double*)&ux;
@@ -4035,6 +4046,9 @@ double CDECL sinh( double x )
     UINT32 w;
     double t, h, absx;
 
+    if (isnan(x))
+        return x;
+
     h = 0.5;
     if (ux >> 63)
         h = -h;
@@ -4331,9 +4345,11 @@ double CDECL tanh( double x )
     if (w > 0x3fe193ea) {
         /* |x| > log(3)/2 ~= 0.5493 or nan */
         if (w > 0x40340000) {
-#if _MSVCR_VER < 140
             if (isnan(x))
+#if _MSVCR_VER < 140
                 return math_error(_DOMAIN, "tanh", x, 0, x);
+#else
+                return x;
 #endif
             /* |x| > 20 or nan */
             /* note: this branch avoids raising overflow */
-- 
2.25.1