revertversion.diff

diff --git a/lib/transaction_ops.c b/lib/transaction_ops.c
index 7dd52e4..38bfda6 100644
--- a/lib/transaction_ops.c
+++ b/lib/transaction_ops.c
@@ -62,10 +62,10 @@ static int
 trans_find_pkg(struct xbps_handle *xhp, const char *pkg, bool reinstall)
 {
 	xbps_dictionary_t pkg_pkgdb = NULL, pkg_repod = NULL;
-	xbps_array_t unsorted, replaces;
-	const char *repoloc, *repopkgver, *instpkgver, *reason;
+	xbps_array_t unsorted, replaces, reverts;
+	const char *repoloc, *repopkgver, *instpkgver, *reason, *revertver;
 	char *self_replaced, *pkgname;
-	int action = 0, rv = 0;
+	int action = 0, rv = 0, vcmp = 0;
 	pkg_state_t state = 0;
 	bool autoinst = false;
 
@@ -109,6 +109,7 @@ trans_find_pkg(struct xbps_handle *xhp, const char *pkg, bool reinstall)
 
 	xbps_dictionary_get_cstring_nocopy(pkg_repod, "pkgver", &repopkgver);
 	xbps_dictionary_get_cstring_nocopy(pkg_repod, "repository", &repoloc);
+	reverts = xbps_dictionary_get(pkg_repod, "reverts");
 
 	if (action == TRANS_UPDATE) {
 		/*
@@ -117,10 +118,27 @@ trans_find_pkg(struct xbps_handle *xhp, const char *pkg, bool reinstall)
 		 */
 		xbps_dictionary_get_cstring_nocopy(pkg_pkgdb,
 		    "pkgver", &instpkgver);
-		if (xbps_cmpver(repopkgver, instpkgver) <= 0) {
+		vcmp = xbps_cmpver(repopkgver, instpkgver);
+
+		if (vcmp < 0) {
+			/*
+			 * Check if the pkg in the repo is explicitly marked to replace a
+			 * specific installed version. This overwrites version comparision.
+			 */
+			for (i = 0; i < xbps_array_count(reverts); i++) {
+				xbps_array_get_cstring_nocopy(reverts, i, &revertsver);
+				if (strcmp(repopkgver, revertver) == 0) {
+					cmp = 1;
+					break;
+				}
+			}
+		}
+
+		if (vcmp <= 0) {
 			xbps_dbg_printf(xhp, "[rpool] Skipping `%s' "
-			    "(installed: %s) from repository `%s'\n",
-			    repopkgver, instpkgver, repoloc);
+					"(installed: %s) from repository `%s'\n",
+					repopkgver, instpkgver, repoloc);
+
 			return EEXIST;
 		}
 	} else if (action == TRANS_REINSTALL) {