From 17f5ce6ce3e549a5a9b41bc69479ddda7299fa13 Mon Sep 17 00:00:00 2001
From: Shiny Nematoda <snematoda.751k2@aleeas.com>
Date: Sat, 16 May 2026 09:57:51 +0200
Subject: [PATCH] fix(issue-search): single exclude query was erroneosly
 considered as must (#12589)

The bleve indexer included a fast path to consider a single token to be of MUST rather than should.
However, the condition missed an additional check and would erroneosly include a NOT as a MUST.

This was not spotted by the tests as such exclude queries were usually made along with another term to avoid noise.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/12589
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
---
 modules/indexer/issues/bleve/bleve.go         | 51 ++++++++++++-------
 .../indexer/issues/internal/tests/tests.go    | 17 +++++++
 2 files changed, 49 insertions(+), 19 deletions(-)

diff --git a/modules/indexer/issues/bleve/bleve.go b/modules/indexer/issues/bleve/bleve.go
index 512788a207..309b2fe6c7 100644
--- a/modules/indexer/issues/bleve/bleve.go
+++ b/modules/indexer/issues/bleve/bleve.go
@@ -151,28 +151,33 @@ func (b *Indexer) Delete(_ context.Context, ids ...int64) error {
 	return batch.Flush()
 }
 
-// Search searches for issues by given conditions.
-// Returns the matching issue IDs
-func (b *Indexer) Search(ctx context.Context, options *internal.SearchOptions) (*internal.SearchResult, error) {
+func termQuery(token internal.Token) query.Query {
+	innerQ := bleve.NewDisjunctionQuery(
+		inner_bleve.MatchPhraseQuery(token.Term, "title", issueIndexerAnalyzer, token.Fuzzy, 2.0),
+		inner_bleve.MatchPhraseQuery(token.Term, "content", issueIndexerAnalyzer, token.Fuzzy, 1.0),
+		inner_bleve.MatchPhraseQuery(token.Term, "comments", issueIndexerAnalyzer, token.Fuzzy, 1.0))
+
+	if issueID, err := token.ParseIssueReference(); err == nil {
+		idQuery := inner_bleve.NumericEqualityQuery(issueID, "index")
+		idQuery.SetBoost(20.0)
+		innerQ.AddQuery(idQuery)
+	}
+	return innerQ
+}
+
+// Create a boolean query with the provided tokens (if any)
+func keywordQuery(tokens []internal.Token) *query.BooleanQuery {
 	q := bleve.NewBooleanQuery()
 
-	for _, token := range options.Tokens {
-		innerQ := bleve.NewDisjunctionQuery(
-			inner_bleve.MatchPhraseQuery(token.Term, "title", issueIndexerAnalyzer, token.Fuzzy, 2.0),
-			inner_bleve.MatchPhraseQuery(token.Term, "content", issueIndexerAnalyzer, token.Fuzzy, 1.0),
-			inner_bleve.MatchPhraseQuery(token.Term, "comments", issueIndexerAnalyzer, token.Fuzzy, 1.0))
-
-		if issueID, err := token.ParseIssueReference(); err == nil {
-			idQuery := inner_bleve.NumericEqualityQuery(issueID, "index")
-			idQuery.SetBoost(20.0)
-			innerQ.AddQuery(idQuery)
-		}
-
-		if len(options.Tokens) == 1 {
-			q.AddMust(innerQ)
-			break
-		}
+	// If there is only a single term the user is likely looking for
+	// a MUST rather than a SHOULD
+	if len(tokens) == 1 && tokens[0].Kind != internal.BoolOptNot {
+		q.AddMust(termQuery(tokens[0]))
+		return q
+	}
 
+	for _, token := range tokens {
+		innerQ := termQuery(token)
 		switch token.Kind {
 		case internal.BoolOptMust:
 			q.AddMust(innerQ)
@@ -183,6 +188,14 @@ func (b *Indexer) Search(ctx context.Context, options *internal.SearchOptions) (
 		}
 	}
 
+	return q
+}
+
+// Search searches for issues by given conditions.
+// Returns the matching issue IDs
+func (b *Indexer) Search(ctx context.Context, options *internal.SearchOptions) (*internal.SearchResult, error) {
+	q := keywordQuery(options.Tokens)
+
 	var filters []query.Query
 	if len(options.RepoIDs) > 0 || options.AllPublic {
 		var repoQueries []query.Query
diff --git a/modules/indexer/issues/internal/tests/tests.go b/modules/indexer/issues/internal/tests/tests.go
index c4a453c9aa..d9428d1af4 100644
--- a/modules/indexer/issues/internal/tests/tests.go
+++ b/modules/indexer/issues/internal/tests/tests.go
@@ -171,6 +171,23 @@ var cases = []*testIndexerCase{
 		ExpectedIDs:   []int64{1002},
 		ExpectedTotal: 1,
 	},
+	{
+		Name: "Keyword Exclude Only",
+		ExtraData: []*internal.IndexerData{
+			{ID: 1000, Title: "hello"},
+			{ID: 1001, Content: "hello world"},
+			{ID: 1002, Comments: []string{"hi", "hello world"}},
+		},
+		Keyword: "-hello",
+		SearchOptions: &internal.SearchOptions{
+			SortBy: internal.SortByCreatedDesc,
+		},
+		Expected: func(t *testing.T, data map[int64]*internal.IndexerData, result *internal.SearchResult) {
+			for _, hit := range result.Hits {
+				assert.NotContains(t, []int64{1000, 1001, 1002}, hit.ID)
+			}
+		},
+	},
 	{
 		Name: "Keyword Fuzzy",
 		ExtraData: []*internal.IndexerData{