1 files changed, 17 insertions, 4 deletions
diff --git a/src/zerror.c b/src/zerror.c
index c59b092..e4ed427 100644
--- a/src/zerror.c
+++ b/src/zerror.c
@@ -2,6 +2,13 @@
 #include "internals.h"
 
 
+#define LIST_ERRORS\
+	X(ZERROR_0_POW_0,  "indeterminate form: 0:th power of 0")\
+	X(ZERROR_0_DIV_0,  "indeterminate form: 0 divided by 0")\
+	X(ZERROR_DIV_0,    "undefined result: division by 0")\
+	X(ZERROR_NEGATIVE, "argument must be non-negative")
+
+
 enum zerror
 zerror(const char **desc)
 {
@@ -10,10 +17,16 @@ zerror(const char **desc)
 			*desc = strerror(libzahl_error);
 		errno = libzahl_error;
 		return ZERROR_ERRNO_SET;
-	} else {
-		/* Current, we should not be able to get here. */
-		if (desc)
+	}
+
+	if (desc) {
+		switch (-libzahl_error) {
+#define X(V, D) case V: *desc = D; break;
+		LIST_ERRORS
+#undef X
+		default:
 			abort();
-		return -libzahl_error;
+		}
 	}
+	return -libzahl_error;
 }