Call getDisplayStrings with a valid range of model indices

It's nicer if clients can rely on the indices being valid, and don't have to
clamp themselves.

pkg/gui/context/list_context_trait.go

@@ -63,7 +63,7 @@ func (self *ListContextTrait) renderLines(startIdx int, endIdx int) string {
 		columnAlignments = self.getColumnAlignments()
 	}
 	return utils.RenderDisplayStrings(
-		self.getDisplayStrings(startIdx, endIdx),
+		self.getDisplayStrings(startIdx, utils.Min(endIdx, self.list.Len())),
 		columnAlignments)
 }
 

pkg/gui/presentation/commits.go

@@ -68,11 +68,10 @@ func GetCommitListDisplayStrings(
 		return nil
 	}
 
-	end := utils.Min(endIdx, len(commits))
 	// this is where my non-TODO commits begin
-	rebaseOffset := utils.Min(indexOfFirstNonTODOCommit(commits), end)
+	rebaseOffset := utils.Min(indexOfFirstNonTODOCommit(commits), endIdx)
 
-	filteredCommits := commits[startIdx:end]
+	filteredCommits := commits[startIdx:endIdx]
 
 	bisectBounds := getbisectBounds(commits, bisectInfo)
 
@@ -85,8 +84,8 @@ func GetCommitListDisplayStrings(
 
 		pipeSets := loadPipesets(commits[rebaseOffset:])
 		pipeSetOffset := utils.Max(startIdx-rebaseOffset, 0)
-		graphPipeSets := pipeSets[pipeSetOffset:utils.Max(end-rebaseOffset, 0)]
-		graphCommits := commits[graphOffset:end]
+		graphPipeSets := pipeSets[pipeSetOffset:utils.Max(endIdx-rebaseOffset, 0)]
+		graphCommits := commits[graphOffset:endIdx]
 		graphLines := graph.RenderAux(
 			graphPipeSets,
 			graphCommits,

pkg/gui/presentation/commits_test.go

@@ -247,7 +247,7 @@ func TestGetCommitListDisplayStrings(t *testing.T) {
 				{Name: "commit5", Sha: "sha5", Parents: []string{"sha7"}},
 			},
 			startIdx:                 1,
-			endIdx:                   11,
+			endIdx:                   5,
 			showGraph:                true,
 			bisectInfo:               git_commands.NewNullBisectInfo(),
 			cherryPickedCommitShaSet: set.New[string](),
@@ -312,7 +312,7 @@ func TestGetCommitListDisplayStrings(t *testing.T) {
 				{Name: "commit5", Sha: "sha5", Parents: []string{"sha7"}},
 			},
 			startIdx:                 4,
-			endIdx:                   6,
+			endIdx:                   5,
 			showGraph:                true,
 			bisectInfo:               git_commands.NewNullBisectInfo(),
 			cherryPickedCommitShaSet: set.New[string](),
@@ -351,7 +351,7 @@ func TestGetCommitListDisplayStrings(t *testing.T) {
 				{Name: "commit3", Sha: "sha3", Parents: []string{"sha4"}},
 			},
 			startIdx:                 0,
-			endIdx:                   5,
+			endIdx:                   3,
 			showGraph:                true,
 			bisectInfo:               git_commands.NewNullBisectInfo(),
 			cherryPickedCommitShaSet: set.New[string](),