(scm_nice): Correction to error detection. Reported by

Matthias Koeppe.

diff --git a/libguile/posix.c b/libguile/posix.c
index d9cfb52..35f6103 100644 (file)
--- a/libguile/posix.c
+++ b/libguile/posix.c
@@ -1422,7 +1422,11 @@ SCM_DEFINE (scm_nice, "nice", 1, 0, 0,
            "The return value is unspecified.")
 #define FUNC_NAME s_scm_nice
 {
-  if (nice (scm_to_int (incr)) != 0)
+  /* nice() returns "prio-NZERO" on success or -1 on error, but -1 can arise
+     from "prio-NZERO", so an error must be detected from errno changed */
+  errno = 0;
+  nice (scm_to_int (incr));
+  if (errno != 0)
     SCM_SYSERROR;
   return SCM_UNSPECIFIED;
 }