From 9e13892e280cf848abf022430f2cbc1f8e214298 Mon Sep 17 00:00:00 2001
From: ailin-nemui <ailin-nemui@users.noreply.github.com>
Date: Mon, 13 May 2019 15:15:46 +0200
Subject: [PATCH] fix realpath on old solaris

POSIX.1-2001 did not implement realpath(..., NULL) yet.
Fixes #1042
---
 src/lib-config/write.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/lib-config/write.c b/src/lib-config/write.c
index b8ef6156..5dbbd1ed 100644
--- a/src/lib-config/write.c
+++ b/src/lib-config/write.c
@@ -315,6 +315,15 @@ int config_write(CONFIG_REC *rec, const char *fname, int create_mode)
 	/* expand all symlinks; else we may replace a symlink with a regular file */
 	dest_name = realpath(base_name, NULL);
 
+	if (errno == EINVAL) {
+		/* variable path length not supported by glibc < 2.3, Solaris < 11 */
+		char resolved_path[PATH_MAX] = { 0 };
+		errno = 0;
+		if ((dest_name = realpath(base_name, resolved_path)) != NULL) {
+			dest_name = g_strdup(dest_name);
+		}
+	}
+
 	if (dest_name == NULL) {
 		if (errno == ENOENT) {
 			dest_name = g_strdup(base_name);