Fix index out of bounds panic when repository has massive tag lists

Co-authored-by: Stefan Haller <stefan@haller-berlin.de>

Author: chojs23

pkg/commands/git_commands/commit_loader.go

@@ -202,6 +202,12 @@ func (self *CommitLoader) MergeRebasingCommits(hashPool *utils.StringPool, commi
 func (self *CommitLoader) extractCommitFromLine(hashPool *utils.StringPool, line string, showDivergence bool) *models.Commit {
 	split := strings.SplitN(line, "\x00", 8)
 
+	// Ensure we have the minimum required fields (at least 7 for basic functionality)
+	if len(split) < 7 {
+		self.Log.Warnf("Malformed git log line: expected at least 7 fields, got %d. Line: %s", len(split), line)
+		return nil
+	}
+
 	hash := split[0]
 	unixTimestamp := split[1]
 	authorName := split[2]
@@ -212,7 +218,12 @@ func (self *CommitLoader) extractCommitFromLine(hashPool *utils.StringPool, line
 		divergence = lo.Ternary(split[5] == "<", models.DivergenceLeft, models.DivergenceRight)
 	}
 	extraInfo := strings.TrimSpace(split[6])
-	message := split[7]
+
+	// message (and the \x00 before it) might not be present if extraInfo is extremely long
+	message := ""
+	if len(split) > 7 {
+		message = split[7]
+	}
 
 	var tags []string
 

pkg/commands/git_commands/commit_loader_test.go

@@ -588,3 +588,115 @@ func TestCommitLoader_setCommitMergedStatuses(t *testing.T) {
 		})
 	}
 }
+
+func TestCommitLoader_extractCommitFromLine(t *testing.T) {
+	common := common.NewDummyCommon()
+	hashPool := &utils.StringPool{}
+
+	loader := &CommitLoader{
+		Common: common,
+	}
+
+	scenarios := []struct {
+		testName       string
+		line           string
+		showDivergence bool
+		expectedNil    bool
+	}{
+		{
+			testName:       "normal commit line with all fields",
+			line:           "0eea75e8c631fba6b58135697835d58ba4c18dbc\x001640826609\x00Jesse Duffield\x00jessedduffield@gmail.com\x00b21997d6b4cbdf84b149\x00>\x00HEAD -> better-tests\x00better typing for rebase mode",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+		{
+			testName:       "normal commit line with left divergence",
+			line:           "hash123\x001234567890\x00John Doe\x00john@example.com\x00parent1 parent2\x00<\x00origin/main\x00commit message",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+		{
+			testName:       "commit line with tags in extraInfo",
+			line:           "abc123\x001640000000\x00Jane Smith\x00jane@example.com\x00parenthash\x00>\x00tag: v1.0, tag: release\x00tagged release",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+		{
+			testName:       "commit line with empty extraInfo",
+			line:           "def456\x001640000000\x00Bob Wilson\x00bob@example.com\x00parenthash\x00>\x00\x00simple commit",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+		{
+			testName:       "commit line with no parents (root commit)",
+			line:           "root123\x001640000000\x00Alice Cooper\x00alice@example.com\x00\x00>\x00\x00initial commit",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+		{
+			testName:       "malformed line with only 3 fields",
+			line:           "hash\x00timestamp\x00author",
+			showDivergence: false,
+			expectedNil:    true,
+		},
+		{
+			testName:       "malformed line with only 4 fields",
+			line:           "hash\x00timestamp\x00author\x00email",
+			showDivergence: false,
+			expectedNil:    true,
+		},
+		{
+			testName:       "malformed line with only 5 fields",
+			line:           "hash\x00timestamp\x00author\x00email\x00parents",
+			showDivergence: false,
+			expectedNil:    true,
+		},
+		{
+			testName:       "malformed line with only 6 fields",
+			line:           "hash\x00timestamp\x00author\x00email\x00parents\x00<",
+			showDivergence: true,
+			expectedNil:    true,
+		},
+		{
+			testName:       "minimal valid line with 7 fields (no message)",
+			line:           "hash\x00timestamp\x00author\x00email\x00parents\x00>\x00extraInfo",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+		{
+			testName:       "minimal valid line with 7 fields (empty extraInfo)",
+			line:           "hash\x00timestamp\x00author\x00email\x00parents\x00>\x00",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+		{
+			testName:       "valid line with 8 fields (complete)",
+			line:           "hash\x00timestamp\x00author\x00email\x00parents\x00<\x00extraInfo\x00message",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+		{
+			testName:       "empty line",
+			line:           "",
+			showDivergence: false,
+			expectedNil:    true,
+		},
+		{
+			testName:       "line with special characters in commit message",
+			line:           "special123\x001640000000\x00Dev User\x00dev@example.com\x00parenthash\x00>\x00\x00fix: handle \x00 null bytes and 'quotes'",
+			showDivergence: true,
+			expectedNil:    false,
+		},
+	}
+
+	for _, scenario := range scenarios {
+		t.Run(scenario.testName, func(t *testing.T) {
+			result := loader.extractCommitFromLine(hashPool, scenario.line, scenario.showDivergence)
+			if scenario.expectedNil {
+				assert.Nil(t, result)
+			} else {
+				assert.NotNil(t, result)
+			}
+		})
+	}
+}