Fix MinGW build broken by recent update from Gnulib

Gnulib moved the prototypes of 'sig2str' and 'str2sig' from
sig2str.h to signal.h, but MinGW does not use the Gnulib
signal.h header, and doesn't have these functions in its
own signal.h.
* lib/sig2str.h (SIG2STR_MAX, sig2str, str2sig): Define and
prototype if not already defined.

(cherry picked from commit b737c6125d69497ad5d2a29d4b5a2b17698992e5)

diff --git a/lib/sig2str.h b/lib/sig2str.h
index 1abdb140e5ae47504fa74a0eb4d4dc1f22d3472f..03d50c94317a0a8dcf85efac65be83772fafdfd9 100644 (file)
--- a/lib/sig2str.h
+++ b/lib/sig2str.h
@@ -19,6 +19,21 @@
 
 #include <signal.h>
 
+/* Maximum size of a signal name returned by sig2str(), including the
+   terminating NUL byte.  */
+#ifndef SIG2STR_MAX
+/* The longest one: "RTMAX", then "+" or "-", then up to 10 digits, then NUL.
+   Add + 2 as a reserve for the future.  */
+# define SIG2STR_MAX (5 + 1 + 10 + 1 + 2)
+#endif
+
+#ifndef HAVE_SIG2STR
+int sig2str (int, char *);
+#endif
+#ifndef HAVE_STR2SIG
+int str2sig (char const *, int *);
+#endif
+
 /* An upper bound on signal numbers allowed by the system.  */
 
 #if defined _sys_nsig