From 3c38ec62dc94d3f018722d7e7aeba46b83d92df7 Mon Sep 17 00:00:00 2001
From: Jan-Lukas Else <mail@jlelse.de>
Date: Sun, 14 Nov 2021 07:58:49 +0100
Subject: [PATCH] Reuse skipped shortpath ids

---
 postsDb_test.go   | 10 ++++++++++
 shortPath.go      | 11 +++++++++--
 shortPath_test.go |  7 +++++++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/postsDb_test.go b/postsDb_test.go
index a1d2c90..3ead607 100644
--- a/postsDb_test.go
+++ b/postsDb_test.go
@@ -95,6 +95,16 @@ func Test_postsDb(t *testing.T) {
 	must.NoError(err)
 	is.Equal(1, count)
 
+	// Check by taxonomy
+	count, err = app.db.countPosts(&postsRequestConfig{taxonomy: &configTaxonomy{Name: "tags"}})
+	must.NoError(err)
+	is.Equal(1, count)
+
+	// Check by taxonomy value
+	count, err = app.db.countPosts(&postsRequestConfig{taxonomy: &configTaxonomy{Name: "tags"}, taxonomyValue: "A"})
+	must.NoError(err)
+	is.Equal(1, count)
+
 	// Delete post
 	_, err = app.deletePostFromDb("/test/abc")
 	must.NoError(err)
diff --git a/shortPath.go b/shortPath.go
index 4513beb..202adfe 100644
--- a/shortPath.go
+++ b/shortPath.go
@@ -17,9 +17,16 @@ func (db *database) shortenPath(p string) (string, error) {
 			return spi.(string), nil
 		}
 		// Insert in case it isn't shortened yet
-		_, err := db.exec("insert or rollback into shortpath (path) values (@path)", sql.Named("path", p))
+		_, err := db.exec(`
+		insert or rollback into shortpath (id, path)
+		values (
+			-- next available id (reuse skipped ids due to bug)
+			(select min(id) + 1 from (select id from shortpath union all select 0) where id + 1 not in (select id from shortpath)),
+			@path
+		)`, sql.Named("path", p))
 		if err != nil {
-			if no, ok := err.(sqlite3.Error); !ok || no.Code != sqlite3.ErrConstraint {
+			if no, ok := err.(sqlite3.Error); !ok || sqlite3.ErrNo(no.ExtendedCode) != sqlite3.ErrNo(sqlite3.ErrConstraintUnique) {
+				// Some other error than unique constraint violation because path is already shortened
 				return nil, err
 			}
 		}
diff --git a/shortPath_test.go b/shortPath_test.go
index 82365bb..b470a52 100644
--- a/shortPath_test.go
+++ b/shortPath_test.go
@@ -35,4 +35,11 @@ func Test_shortenPath(t *testing.T) {
 
 	assert.NotEqual(t, res1, res3)
 	assert.Equal(t, "/s/2", res3)
+
+	db.spc.Delete("/a")
+	db.exec("delete from shortpath where id = 1")
+
+	res4, err := db.shortenPath("/c")
+	require.NoError(t, err)
+	assert.Equal(t, "/s/1", res4)
 }