syscall: Force first letter of error message to lower case.

From-SVN: r193449

libgo/go/syscall/errstr.go

@@ -6,22 +6,27 @@
 
 package syscall
 
-//sysnb	strerror_r(errnum int, buf []byte) (err error)
+//sysnb	strerror_r(errnum int, buf []byte) (err Errno)
 //strerror_r(errnum _C_int, buf *byte, buflen Size_t) _C_int
 
 func Errstr(errnum int) string {
 	for len := 128; ; len *= 2 {
 		b := make([]byte, len)
-		err := strerror_r(errnum, b)
-		if err == nil {
+		errno := strerror_r(errnum, b)
+		if errno == 0 {
 			i := 0
 			for b[i] != 0 {
 				i++
 			}
+			// Lowercase first letter: Bad -> bad, but
+			// STREAM -> STREAM.
+			if i > 1 && 'A' <= b[0] && b[0] <= 'Z' && 'a' <= b[1] && b[1] <= 'z' {
+				b[0] += 'a' - 'A'
+			}
 			return string(b[:i])
 		}
-		if err != ERANGE {
-			return "Errstr failure"
+		if errno != ERANGE {
+			return "errstr failure"
 		}
 	}
 }

libgo/go/syscall/errstr_linux.go

@@ -19,5 +19,10 @@ func Errstr(errnum int) string {
 	for b[i] != 0 {
 		i++
 	}
+	// Lowercase first letter: Bad -> bad, but STREAM -> STREAM.
+	if i > 1 && 'A' <= b[0] && b[0] <= 'Z' && 'a' <= b[1] && b[1] <= 'z' {
+		c := b[0] + 'a' - 'A'
+		return string(c) + string(b[1:i])
+	}
 	return string(b[:i])
 }

libgo/go/syscall/errstr_nor.go

@@ -25,7 +25,15 @@ func Errstr(errno int) string {
 	for b[i] != 0 {
 		i++
 	}
-	s := string(b[:i])
+
+	// Lowercase first letter: Bad -> bad, but STREAM -> STREAM.
+	var s string
+	if i > 1 && 'A' <= b[0] && b[0] <= 'Z' && 'a' <= b[1] && b[1] <= 'z' {
+		c := b[0] + 'a' - 'A'
+		s = string(c) + string(b[1:i])
+	} else {
+		s = string(b[:i])
+	}
 
 	errstr_lock.Unlock()