From: Nathan Wagner <nw@hydaspes.if.org>
Date: Sun, 9 Dec 2018 11:40:40 +0000 (+0000)
Subject: add check for symlink removal in syncfs
X-Git-Tag: v0.4.3~8
X-Git-Url: https://pd.if.org/git/?p=zpackage;a=commitdiff_plain;h=f523c503b7afe9964eb2c659f42c3cabbe725ae2

add check for symlink removal in syncfs

Creating a symlink will error if the file already exists, so we check
for a symlink with a different target and mark it for removal before
creation.  This has a small race condition, and there may be a case
where the old symlink gets deleted but the new one does not get created.
---

diff --git a/zpm-syncfs.c b/zpm-syncfs.c
index c630963..2360f7c 100644
--- a/zpm-syncfs.c
+++ b/zpm-syncfs.c
@@ -841,6 +841,14 @@ static int install(struct config *conf, struct nitem *item, unsigned int flags)
 
 	source = conf->src ? conf->src : conf->log;
 
+	if (mkleading) {
+		rv = create_leading_dirs(item->dest);
+		if (!rv) {
+			setsyserr(conf, "can't create leading dirs for %s", item->dest);
+			return failure;
+		}
+	}
+
 	if (unlink_file) {
 		rv = remove_existing(conf, item->dest);
 	} else if (rm_dir) {
@@ -851,14 +859,6 @@ static int install(struct config *conf, struct nitem *item, unsigned int flags)
 		return failure;
 	}
 
-	if (mkleading) {
-		rv = create_leading_dirs(item->dest);
-		if (!rv) {
-			setsyserr(conf, "can't create leading dirs for %s", item->dest);
-			return failure;
-		}
-	}
-
 	errno = 0;
 	switch (item->ftype) {
 		case 'r': rv = zpm_extract(source, item->hash, item->dest, item->mode);
@@ -1278,13 +1278,14 @@ static int install_files(void *f, int ncols, char **vals, char **cols) {
 				/* fix md */
 				return set_md(conf, &nitem);
 			}
-			if (mdsame && !hashsame) {
-				/* install */
-				return install(conf, &nitem, 3);
-			}
-			if (!mdsame && !hashsame) {
-				/* install */
-				return install(conf, &nitem, 3);
+
+			if (!hashsame) {
+				/* doesn't matter on the md */
+				int flags = INS_MD | INS_CLD;
+				if (nitem.ftype == 'l') {
+					flags |= INS_UNLINK;
+				}
+				return install(conf, &nitem, flags);
 			}
 		}