Relax ttyname_r error checks

* src/engine-assuan.c (llass_new): Don't treat ttyname_r error as
fatal.
* src/engine-g13.c (g13_new): Likewise.
* src/engine-gpg.c (gpg_new): Likewise.
* src/engine-gpgsm.c (gpgsm_new): Likewise.
* src/engine-uiserver.c (uiserver_new): Likewise.

--
Even though isatty() returns 1, ttyname_r() may fail in many ways, e.g.,
when /dev/pts is not accessible under chroot.  Since all our uses of
ttyname_r() require that the function works, we can treat the failure as
if isatty() fails.

Signed-off-by: Daiki Ueno <ueno@gnu.org>

src/engine-assuan.c

@@ -282,12 +282,10 @@ llass_new (void **engine, const char *file_name, const char *home_dir)
       char *dft_ttytype = NULL;
 
       rc = ttyname_r (1, dft_ttyname, sizeof (dft_ttyname));
-      if (rc)
+
-	{
+      /* Even though isatty() returns 1, ttyname_r() may fail in many
-	  err = gpg_error_from_errno (rc);
+	 ways, e.g., when /dev/pts is not accessible under chroot.  */
-	  goto leave;
+      if (!rc)
-	}
-      else
 	{
 	  if (asprintf (&optstr, "OPTION ttyname=%s", dft_ttyname) < 0)
 	    {

src/engine-g13.c

@@ -286,12 +286,10 @@ g13_new (void **engine, const char *file_name, const char *home_dir)
       int rc;
 
       rc = ttyname_r (1, dft_ttyname, sizeof (dft_ttyname));
-      if (rc)
+
-	{
+      /* Even though isatty() returns 1, ttyname_r() may fail in many
-	  err = gpg_error_from_errno (rc);
+	 ways, e.g., when /dev/pts is not accessible under chroot.  */
-	  goto leave;
+      if (!rc)
-	}
-      else
 	{
 	  if (asprintf (&optstr, "OPTION ttyname=%s", dft_ttyname) < 0)
 	    {

src/engine-gpg.c

@@ -513,6 +513,8 @@ gpg_new (void **engine, const char *file_name, const char *home_dir)
 	rc = add_arg (gpg, dft_display);
 
       free (dft_display);
+      if (rc)
+	goto leave;
     }
 
   if (isatty (1))
@@ -520,9 +522,10 @@ gpg_new (void **engine, const char *file_name, const char *home_dir)
       int err;
 
       err = ttyname_r (1, dft_ttyname, sizeof (dft_ttyname));
-      if (err)
+
-	rc = gpg_error_from_errno (err);
+      /* Even though isatty() returns 1, ttyname_r() may fail in many
-      else
+	 ways, e.g., when /dev/pts is not accessible under chroot.  */
+      if (!err)
 	{
           if (*dft_ttyname)
             {
@@ -547,10 +550,10 @@ gpg_new (void **engine, const char *file_name, const char *home_dir)
 
 	      free (dft_ttytype);
 	    }
-	}
 	  if (rc)
 	    goto leave;
 	}
+    }
 
  leave:
   if (rc)

src/engine-gpgsm.c

@@ -408,12 +408,10 @@ gpgsm_new (void **engine, const char *file_name, const char *home_dir)
       int rc;
 
       rc = ttyname_r (1, dft_ttyname, sizeof (dft_ttyname));
-      if (rc)
+
-	{
+      /* Even though isatty() returns 1, ttyname_r() may fail in many
-	  err = gpg_error_from_errno (rc);
+	 ways, e.g., when /dev/pts is not accessible under chroot.  */
-	  goto leave;
+      if (!rc)
-	}
-      else
 	{
 	  if (asprintf (&optstr, "OPTION ttyname=%s", dft_ttyname) < 0)
 	    {

src/engine-uiserver.c

@@ -326,12 +326,10 @@ uiserver_new (void **engine, const char *file_name, const char *home_dir)
       int rc;
 
       rc = ttyname_r (1, dft_ttyname, sizeof (dft_ttyname));
-      if (rc)
+
-	{
+      /* Even though isatty() returns 1, ttyname_r() may fail in many
-	  err = gpg_error_from_errno (rc);
+	 ways, e.g., when /dev/pts is not accessible under chroot.  */
-	  goto leave;
+      if (!rc)
-	}
-      else
 	{
 	  if (asprintf (&optstr, "OPTION ttyname=%s", dft_ttyname) < 0)
 	    {