On Linux, wcwidth() needs _XOPEN_SOURCE, or just _GNU_SOURCE for simplicity.

Besides, signedness of wchar_t and wint_t may differ, it i only
guaranteed that each wchar_t can be represented as a wint_t.
A problem report by Daniel Levai reminded me to fix this.

2 files changed, 6 insertions, 2 deletions

diff --git a/configure b/configure
index baa05ad4..0fb841cf 100755
--- a/configure
+++ b/configure
@@ -253,7 +253,7 @@ cat << __HEREDOC__
 #define MANDOC_CONFIG_H
 
 #if defined(__linux__) || defined(__MINT__)
-#define _GNU_SOURCE /* getsubopt(), strcasestr(), strptime() */
+#define _GNU_SOURCE	/* See test-*.c what needs this. */
 #endif
 
 __HEREDOC__
diff --git a/test-wchar.c b/test-wchar.c
index 0dc85ea4..72f4844e 100644
--- a/test-wchar.c
+++ b/test-wchar.c
@@ -15,6 +15,10 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+#if defined(__linux__) || defined(__MINT__)
+#define _GNU_SOURCE /* wcwidth() */
+#endif
+
 #include <locale.h>
 #include <stdio.h>
 #include <wchar.h>
@@ -50,7 +54,7 @@ main(void)
 
 	dup2(STDERR_FILENO, STDOUT_FILENO);
 	wc = L'*';
-	if (putwchar(wc) != wc) {
+	if (putwchar(wc) != (wint_t)wc) {
 		fputs("bad putwchar return value\n", stderr);
 		return(1);
 	}