Merge branch 'macos10.15-compile-fixes' into 'master'

Compile fixes for macOS 10.15 and later

See merge request sane-project/frontends!8

sanei/sanei_init_debug.c

@@ -97,30 +97,31 @@ sanei_debug_msg
   (int level, int max_level, const char *be, const char *fmt, va_list ap)
 {
   char *msg;
-	
+
   if (max_level >= level)
     {
-      if ( 1 == isfdtype(fileno(stderr), S_IFSOCK) )
-	{
-	  msg = (char *)malloc (sizeof(char) * (strlen(be) + strlen(fmt) + 4));
-	  if (msg == NULL)
-	    {
-	      syslog (LOG_DEBUG, "[sanei_debug] malloc() failed\n");
-	      vsyslog (LOG_DEBUG, fmt, ap);
-	    }
-	  else
-	    {
-	      sprintf (msg, "[%s] %s", be, fmt);
+      struct stat sb;
+      if ( 0 == fstat(fileno(stderr), &sb) && S_IFSOCK == (sb.st_mode & S_IFMT) )
+        {
+          msg = (char *)malloc (sizeof(char) * (strlen(be) + strlen(fmt) + 4));
+          if (msg == NULL)
+            {
+              syslog (LOG_DEBUG, "[sanei_debug] malloc() failed\n");
+              vsyslog (LOG_DEBUG, fmt, ap);
+            }
+          else
+            {
+              sprintf (msg, "[%s] %s", be, fmt);
               vsyslog(LOG_DEBUG, msg, ap);
-	      free (msg);
-	    }
-	}
+              free (msg);
+            }
+        }
       else
-	{
-	  fprintf (stderr, "[%s] ", be);
+        {
+          fprintf (stderr, "[%s] ", be);
           vfprintf (stderr, fmt, ap);
-	}
-	 
+        }
+
     }
 }