Revert "Merge PR #5812: fix(read): honor exact line selector bounds (@roboomp)"

This reverts commit 58c71d5b50, reversing changes made to 7c7227bc8e.
2026-07-18 22:04:43 +02:00
parent 32dc282517
commit 8f2cd23e39
7 changed files with 185 additions and 87 deletions
@@ -131,6 +131,7 @@
 ### Added

 - Added `PI_CONFIG_FILES`, a platform-delimited (`:` on Unix, `;` on Windows) environment path-list of settings overlays loaded before `--config` overlays, so wrapper scripts can inject settings without argv surgery ([#5685](https://github.com/can1357/oh-my-pi/issues/5685)).
+- Fixed the `/extensions` dashboard tab labeled "Agents (standard)" being confused with the `/agents` subagents feature — the `.agent`/`.agents` config-standard provider now presents as "Agent Dirs (.agent/.agents)" since it lists skills, rules, prompts, commands, and context/system files, never subagents ([#5821](https://github.com/can1357/oh-my-pi/issues/5821)).

 ## [17.0.2] - 2026-07-17

@@ -54,7 +54,7 @@ import {
 } from "../session/streaming-output";
 import { fileHyperlink, renderCodeCell, renderMarkdownCell, renderStatusLine, tryResolveInternalUrlSync } from "../tui";
 import { CachedOutputBlock, markFramedBlockComponent } from "../tui/output-block";
-import { buildLineEntries, type LineEntry, lineEntriesToPlainText } from "../utils/block-context";
+import { buildLineEntriesWithBlockContext, type LineEntry, lineEntriesToPlainText } from "../utils/block-context";
 import { resolveFileDisplayMode } from "../utils/file-display-mode";
 import {
 	ImageInputTooLargeError,
@@ -164,7 +164,7 @@ const PROSE_SUMMARY_EXTENSIONS = new Set([".md", ".txt"]);
 // Remote mount path prefix (sshfs mounts) - skip fuzzy matching to avoid hangs
 const REMOTE_MOUNT_PREFIX = getRemoteDir() + path.sep;

-async function readSmallFileLines(absolutePath: string, fileSize: number): Promise<string[] | undefined> {
+async function readBracketContextFullLines(absolutePath: string, fileSize: number): Promise<string[] | undefined> {
 	if (fileSize > SNAPSHOT_MAX_BYTES) return undefined;
 	try {
 		return normalizeToLF(await Bun.file(absolutePath).text()).split("\n");
@@ -395,6 +395,40 @@ function formatSummaryElisionFooter(
 }
 const READ_CHUNK_SIZE = 8 * 1024;

+/**
+ * Context lines added around an explicit range read. Anchor-stale failures
+ * cluster on edits whose anchors land just outside the most recent read
+ * window, but the data (`scripts/session-stats/analyze_selector_reads.py`)
+ * shows most follow-up reads are disjoint hops, not adjacent extensions —
+ * so symmetric padding rarely pays for itself.
+ *
+ * Leading=1 catches accidental single-line reads where the anchor is the
+ * line immediately above the requested start. Trailing=3 buffers the
+ * common case where the agent asks for a narrow range and then needs the
+ * next few lines to disambiguate an anchor.
+ */
+const RANGE_LEADING_CONTEXT_LINES = 1;
+const RANGE_TRAILING_CONTEXT_LINES = 3;
+
+/**
+ * Expand a [start, end) range with leading/trailing context lines on the
+ * sides where the user actually constrained the range. A start of 0 (no
+ * explicit offset) does not get leading context — that's already an
+ * open-ended read from the top.
+ */
+function expandRangeWithContext(
+	requestedStart: number,
+	requestedEnd: number,
+	totalLines: number,
+	expandStart: boolean,
+	expandEnd: boolean,
+): { startLine: number; endLine: number } {
+	return {
+		startLine: expandStart ? Math.max(0, requestedStart - RANGE_LEADING_CONTEXT_LINES) : requestedStart,
+		endLine: expandEnd ? Math.min(totalLines, requestedEnd + RANGE_TRAILING_CONTEXT_LINES) : requestedEnd,
+	};
+}
+
 async function streamLinesFromFile(
 	filePath: string,
 	startLine: number,
@@ -1271,10 +1305,26 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 		const details = options.details ?? {};
 		const allLines = text.split("\n");
 		const totalLines = allLines.length;
+		// User-requested 0-indexed range start. Lines BEFORE this are leading
+		// context (added below if offset is explicit).
 		const requestedStart = offset ? Math.max(0, offset - 1) : 0;
-		const startLine = requestedStart;
 		const ignoreResultLimits = options.ignoreResultLimits ?? false;
-		const endLine = limit !== undefined ? Math.min(startLine + limit, allLines.length) : allLines.length;
+		const requestedEnd = limit !== undefined ? Math.min(requestedStart + limit, allLines.length) : allLines.length;
+		// Expand only on sides the user actually constrained: leading context
+		// when offset>1, trailing context when a finite limit was set. Raw mode
+		// never expands — without line numbers the padding is indistinguishable
+		// from requested content, so `raw:31-31` must return line 31 and nothing
+		// else (verbatim-extraction contract).
+		const rawDisplay = options.raw === true;
+		const expanded = expandRangeWithContext(
+			requestedStart,
+			requestedEnd,
+			allLines.length,
+			!rawDisplay && offset !== undefined && offset > 1,
+			!rawDisplay && limit !== undefined,
+		);
+		const startLine = expanded.startLine;
+		const endLineExpanded = expanded.endLine;
 		const startLineDisplay = startLine + 1;

 		const resultBuilder = toolResult(details);
@@ -1300,6 +1350,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 				.done();
 		}

+		const endLine = endLineExpanded;
 		const selectedContent = allLines.slice(startLine, endLine).join("\n");
 		const userLimitedLines = limit !== undefined ? endLine - startLine : undefined;
 		const truncation = ignoreResultLimits ? noTruncResult(selectedContent) : truncateHead(selectedContent);
@@ -1344,8 +1395,10 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 			emittedHashlineHeader = true;
 			return prependHashlineHeader(formatted, hashContext);
 		};
-		const buildSelectedLineEntries = (endLineDisplay: number): LineEntry[] =>
-			buildLineEntries(allLines, [{ startLine: startLineDisplay, endLine: endLineDisplay }]);
+		const buildLineEntries = (endLineDisplay: number): LineEntry[] =>
+			buildLineEntriesWithBlockContext(allLines, [{ startLine: startLineDisplay, endLine: endLineDisplay }], {
+				path: options.sourcePath,
+			});

 		let outputText: string;
 		let truncationInfo:
@@ -1383,7 +1436,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 				rawSeenLines = contiguousLineNumbers(startLineDisplay, outputLines);
 				outputText = formatText(truncation.content, startLineDisplay);
 			} else {
-				outputText = formatLineEntries(buildSelectedLineEntries(endLineDisplay), startLineDisplay);
+				outputText = formatLineEntries(buildLineEntries(endLineDisplay), startLineDisplay);
 			}
 			details.truncation = truncation;
 			truncationInfo = {
@@ -1398,7 +1451,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 				rawSeenLines = contiguousLineNumbers(startLineDisplay, userLimitedLines);
 				outputText = formatText(selectedContent, startLineDisplay);
 			} else {
-				outputText = formatLineEntries(buildSelectedLineEntries(endLine), startLineDisplay);
+				outputText = formatLineEntries(buildLineEntries(endLine), startLineDisplay);
 			}
 			outputText += `\n\n[${remaining} more lines in ${options.entityLabel}. Use :${nextOffset} to continue]`;
 		} else {
@@ -1406,7 +1459,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 				rawSeenLines = contiguousLineNumbers(startLineDisplay, endLine - startLine);
 				outputText = formatText(truncation.content, startLineDisplay);
 			} else {
-				outputText = formatLineEntries(buildSelectedLineEntries(endLine), startLineDisplay);
+				outputText = formatLineEntries(buildLineEntries(endLine), startLineDisplay);
 			}
 		}

@@ -1427,8 +1480,8 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 	 * Render a multi-range read against in-memory text. Each range emits a
 	 * formatted block with its own anchors / line numbers, blocks are joined
 	 * with an elision separator, and ranges past EOF surface as `[…]` notices
-	 * so the model can correct the next call. Context is never added because
-	 * multi-range callers always specify exact bounds.
+	 * so the model can correct the next call. No leading/trailing context is
+	 * added — multi-range callers always specify exact bounds.
 	 */
 	#buildInMemoryMultiRangeResult(
 		text: string,
@@ -1485,7 +1538,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 		if (options.raw === true) {
 			outputText = rawParts.length > 0 ? rawParts.join("\n\n…\n\n") : "";
 		} else if (visibleSpans.length > 0) {
-			const entries = buildLineEntries(allLines, visibleSpans);
+			const entries = buildLineEntriesWithBlockContext(allLines, visibleSpans, { path: options.sourcePath });
 			if (shouldAddHashLines) seenLines = lineNumbersFromEntries(entries);
 			const firstLine = entries.find(entry => entry.kind === "line");
 			if (firstLine?.kind === "line") {
@@ -1569,7 +1622,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 		const notices: string[] = [];
 		const visibleSpans: Array<{ startLine: number; endLine: number }> = [];
 		const displayLineByNumber = new Map<number, string>();
-		const fullLines = rawSelector ? undefined : await readSmallFileLines(absolutePath, fileSize);
+		const fullLines = rawSelector ? undefined : await readBracketContextFullLines(absolutePath, fileSize);
 		let columnTruncated = 0;
 		let displayContent: { text: string; startLine: number; lineNumbers?: Array<number | null> } | undefined;

@@ -1637,9 +1690,23 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {

 		let outputText: string;
 		if (!rawSelector && fullLines && visibleSpans.length > 0) {
-			const entries = buildLineEntries(fullLines, visibleSpans, {
-				lineText: (lineNumber, sourceText) => displayLineByNumber.get(lineNumber) ?? sourceText,
-			});
+			const entries = buildLineEntriesWithBlockContext(
+				fullLines,
+				visibleSpans,
+				{ path: absolutePath },
+				{
+					lineText: (lineNumber, sourceText) => {
+						const visibleText = displayLineByNumber.get(lineNumber);
+						if (visibleText !== undefined) return visibleText;
+						if (maxColumns <= 0) return sourceText;
+						const truncated = truncateLine(sourceText, maxColumns);
+						if (truncated.wasTruncated) {
+							columnTruncated = maxColumns;
+						}
+						return truncated.text;
+					},
+				},
+			);
 			const firstLine = entries.find(entry => entry.kind === "line");
 			displayContent = {
 				text: lineEntriesToPlainText(entries, BRACKET_CONTEXT_ELLIPSIS),
@@ -2446,7 +2513,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 					// Raw text or line-range mode
 					const { offset, limit } = selToOffsetLimit(parsed);
 					// Try ACP bridge first — editor's in-memory buffer is source of truth.
-					// Request full text so local range rendering preserves exact bounds and line numbers.
+					// Request full text so local range rendering keeps normal context and line numbers.
 					const bridgePromise = this.#routeReadThroughBridge(absolutePath);
 					if (bridgePromise !== undefined) {
 						try {
@@ -2468,15 +2535,24 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 						}
 					}

+					// User-requested 0-indexed range start. Lines BEFORE this become
+					// leading context (added below if offset is explicit). Raw mode
+					// never adds context: without line numbers the padding is
+					// indistinguishable from requested content, so `raw:31-31` must
+					// return line 31 and nothing else.
 					const rawSelector = isRawSelector(parsed);
 					const requestedStart = offset ? Math.max(0, offset - 1) : 0;
-					const startLine = requestedStart;
+					const expandStart = !rawSelector && offset !== undefined && offset > 1;
+					const expandEnd = !rawSelector && limit !== undefined;
+					const leadingContext = expandStart ? Math.min(requestedStart, RANGE_LEADING_CONTEXT_LINES) : 0;
+					const trailingContext = expandEnd ? RANGE_TRAILING_CONTEXT_LINES : 0;
+					const startLine = requestedStart - leadingContext;
 					const startLineDisplay = startLine + 1;

 					const DEFAULT_LIMIT = this.#defaultLimit;
 					const effectiveLimit = limit ?? DEFAULT_LIMIT;
-					const maxLinesToCollect = Math.min(effectiveLimit, DEFAULT_MAX_LINES);
-					const selectedLineLimit = effectiveLimit;
+					const maxLinesToCollect = Math.min(effectiveLimit + leadingContext + trailingContext, DEFAULT_MAX_LINES);
+					const selectedLineLimit = effectiveLimit + leadingContext + trailingContext;
 					// Scale byte budget with line limit so the configured line count actually fits.
 					// Assume ~512 bytes/line average; never go below the shared default.
 					const maxBytesForRead = Math.max(DEFAULT_MAX_BYTES, maxLinesToCollect * 512);
@@ -2538,6 +2614,15 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 						if (cloned) displayLines = cloned;
 					}

+					const displayLineByNumber = new Map<number, string>();
+					for (let i = 0; i < displayLines.length; i++) {
+						displayLineByNumber.set(startLineDisplay + i, displayLines[i] ?? "");
+					}
+					const bracketContextFullLines = rawSelector
+						? undefined
+						: await readBracketContextFullLines(absolutePath, fileSize);
+					const displayedEndLine = startLineDisplay + Math.max(0, displayLines.length - 1);
+
 					const selectedContent = displayLines.join("\n");
 					const userLimitedLines = collectedLines.length;

@@ -2594,6 +2679,36 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 						emittedHashlineHeader = true;
 						return prependHashlineHeader(formatted, hashContext);
 					};
+					const formatBracketAwareText = (): string | undefined => {
+						if (!bracketContextFullLines) return undefined;
+						const entries = buildLineEntriesWithBlockContext(
+							bracketContextFullLines,
+							[{ startLine: startLineDisplay, endLine: displayedEndLine }],
+							{ path: absolutePath },
+							{
+								lineText: (lineNumber, sourceText) => {
+									const visibleText = displayLineByNumber.get(lineNumber);
+									if (visibleText !== undefined) return visibleText;
+									if (maxColumns <= 0) return sourceText;
+									const truncated = truncateLine(sourceText, maxColumns);
+									if (truncated.wasTruncated) {
+										columnTruncated = maxColumns;
+									}
+									return truncated.text;
+								},
+							},
+						);
+						const firstLine = entries.find(entry => entry.kind === "line");
+						capturedDisplayContent = {
+							text: lineEntriesToPlainText(entries, BRACKET_CONTEXT_ELLIPSIS),
+							startLine: firstLine?.kind === "line" ? firstLine.lineNumber : startLineDisplay,
+							lineNumbers: entries.map(entry => (entry.kind === "line" ? entry.lineNumber : null)),
+						};
+						const formatted = formatLineEntriesWithMode(entries, shouldAddHashLines, shouldAddLineNumbers);
+						if (!hashContext || emittedHashlineHeader) return formatted;
+						emittedHashlineHeader = true;
+						return prependHashlineHeader(formatted, hashContext);
+					};

 					let outputText: string;

@@ -2624,7 +2739,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 							},
 						};
 					} else if (truncation.truncated) {
-						outputText = formatText(truncation.content, startLineDisplay);
+						outputText = formatBracketAwareText() ?? formatText(truncation.content, startLineDisplay);
 						details = { truncation };
 						sourcePath = absolutePath;
 						truncationInfo = {
@@ -2638,7 +2753,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 					} else if (startLine + userLimitedLines < totalFileLines || !reachedEof) {
 						const nextOffset = startLine + userLimitedLines + 1;

-						outputText = formatText(truncation.content, startLineDisplay);
+						outputText = formatBracketAwareText() ?? formatText(truncation.content, startLineDisplay);
 						outputText += reachedEof
 							? `\n\n[${totalFileLines - (startLine + userLimitedLines)} more lines in file. Use :${nextOffset} to continue]`
 							: `\n\n[More lines in file (${formatBytes(fileSize)} total; not scanned to EOF). Use :${nextOffset} to continue]`;
@@ -2646,7 +2761,7 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {
 						sourcePath = absolutePath;
 					} else {
 						// No truncation, no user limit exceeded
-						outputText = formatText(truncation.content, startLineDisplay);
+						outputText = formatBracketAwareText() ?? formatText(truncation.content, startLineDisplay);
 						details = {};
 						sourcePath = absolutePath;
 					}
@@ -2866,11 +2981,16 @@ export class ReadTool implements AgentTool<typeof readSchema, ReadToolDetails> {

 		const { offset, limit } = selToOffsetLimit(parsedSel);
 		const requestedStart = offset ? Math.max(0, offset - 1) : 0;
-		const startLine = requestedStart;
+		// Raw mode never adds context lines — see the plain-file range path.
+		const expandStart = !rawSelector && offset !== undefined && offset > 1;
+		const expandEnd = !rawSelector && limit !== undefined;
+		const leadingContext = expandStart ? Math.min(requestedStart, RANGE_LEADING_CONTEXT_LINES) : 0;
+		const trailingContext = expandEnd ? RANGE_TRAILING_CONTEXT_LINES : 0;
+		const startLine = requestedStart - leadingContext;
 		const startLineDisplay = startLine + 1;
 		const effectiveLimit = limit ?? this.#defaultLimit;
-		const maxLinesToCollect = Math.min(effectiveLimit, DEFAULT_MAX_LINES);
-		const selectedLineLimit = effectiveLimit;
+		const maxLinesToCollect = Math.min(effectiveLimit + leadingContext + trailingContext, DEFAULT_MAX_LINES);
+		const selectedLineLimit = effectiveLimit + leadingContext + trailingContext;
 		const maxBytesForRead = Math.max(DEFAULT_MAX_BYTES, maxLinesToCollect * 512);
 		const streamResult = await streamLinesFromFile(
 			artifact.path,
@@ -266,24 +266,27 @@ export function findBlockContextLines(
 	return nativeBlockContext(fullLines, visible, source) ?? lexicalBracketContext(fullLines, visible);
 }

-interface LineEntryOptions {
-	lineText?: (lineNumber: number, sourceText: string, context: boolean) => string;
-}
-
-function buildEntries(
+/**
+ * Build display entries for `visibleSpans` plus any off-window block-boundary
+ * lines, in source order, with `{ kind: "ellipsis" }` markers inserted across
+ * non-contiguous gaps. `options.lineText` lets callers substitute display text
+ * (e.g. column-truncated lines) for a given line number.
+ */
+export function buildLineEntriesWithBlockContext(
 	fullLines: readonly string[],
-	visible: ReadonlySet<number>,
-	context: ReadonlyMap<number, string> | undefined,
-	options: LineEntryOptions,
+	visibleSpans: readonly LineSpan[],
+	source: BlockContextSource = {},
+	options: {
+		lineText?: (lineNumber: number, sourceText: string, context: boolean) => string;
+	} = {},
 ): LineEntry[] {
-	const sorted = [...visible];
-	if (context) {
-		for (const lineNumber of context.keys()) {
-			if (!visible.has(lineNumber)) sorted.push(lineNumber);
-		}
-	}
-	sorted.sort((left, right) => left - right);
+	const spans = normalizeLineSpans(visibleSpans, fullLines.length);
+	const visible = visibleLineNumbers(spans);
+	const context = findBlockContextLines(fullLines, visible, source);
+	const allLines = new Set<number>(visible);
+	for (const lineNumber of context.keys()) allLines.add(lineNumber);

+	const sorted = [...allLines].sort((left, right) => left - right);
 	const entries: LineEntry[] = [];
 	let previousLine: number | undefined;
 	for (const lineNumber of sorted) {
@@ -291,7 +294,7 @@ function buildEntries(
 			entries.push({ kind: "ellipsis" });
 		}
 		const sourceText = fullLines[lineNumber - 1] ?? "";
-		const isContext = context?.has(lineNumber) === true;
+		const isContext = context.has(lineNumber);
 		entries.push({
 			kind: "line",
 			lineNumber,
@@ -304,33 +307,6 @@ function buildEntries(
 	return entries;
 }

-/** Build display entries for exactly the requested spans, separated by ellipses. */
-export function buildLineEntries(
-	fullLines: readonly string[],
-	visibleSpans: readonly LineSpan[],
-	options: LineEntryOptions = {},
-): LineEntry[] {
-	const spans = normalizeLineSpans(visibleSpans, fullLines.length);
-	return buildEntries(fullLines, visibleLineNumbers(spans), undefined, options);
-}
-
-/**
- * Build display entries for `visibleSpans` plus any off-window block-boundary
- * lines, in source order, with `{ kind: "ellipsis" }` markers inserted across
- * non-contiguous gaps. `options.lineText` lets callers substitute display text
- * (e.g. column-truncated lines) for a given line number.
- */
-export function buildLineEntriesWithBlockContext(
-	fullLines: readonly string[],
-	visibleSpans: readonly LineSpan[],
-	source: BlockContextSource = {},
-	options: LineEntryOptions = {},
-): LineEntry[] {
-	const spans = normalizeLineSpans(visibleSpans, fullLines.length);
-	const visible = visibleLineNumbers(spans);
-	return buildEntries(fullLines, visible, findBlockContextLines(fullLines, visible, source), options);
-}
-
 export function lineEntriesToPlainText(entries: readonly LineEntry[], ellipsis = "…"): string {
 	return entries.map(entry => (entry.kind === "ellipsis" ? ellipsis : entry.text)).join("\n");
 }
@@ -79,8 +79,6 @@ describe("read tool multi-range selector", () => {
 		expect(text).toContain("line 20");
 		expect(text).toContain("line 21");
 		expect(text).toContain("line 22");
-		expect(text).not.toMatch(/^2:line 2$/m);
-		expect(text).not.toMatch(/^6:line 6$/m);
 		// Lines between the ranges must be elided
 		expect(text).not.toContain("line 10");
 		expect(text).not.toContain("line 19");
@@ -88,7 +86,7 @@ describe("read tool multi-range selector", () => {
 		expect(text).toContain("…");
 	});

-	it("does not add a closing bracket outside a forward range", async () => {
+	it("includes the matching closing bracket line outside a forward range", async () => {
 		const filePath = path.join(tmpDir, "brackets.ts");
 		await fs.writeFile(
 			filePath,
@@ -108,13 +106,13 @@ describe("read tool multi-range selector", () => {
 		const text = textOutput(await tool.execute("call-bracket-close", { path: `${filePath}:1-1` }));

 		expect(text).toContain("function outer() {");
-		expect(text).not.toContain("…");
-		expect(text).not.toMatch(/^7:}$/m);
+		expect(text).toContain("…");
+		expect(text).toContain("}");
 		expect(text).not.toContain("const four");
 		expect(text).not.toContain("return one + two");
 	});

-	it("does not add an opening bracket outside a reverse range", async () => {
+	it("includes the matching opening bracket line outside a reverse range", async () => {
 		const filePath = path.join(tmpDir, "brackets.ts");
 		await fs.writeFile(
 			filePath,
@@ -133,14 +131,13 @@ describe("read tool multi-range selector", () => {
 		const tool = new ReadTool(createSession(tmpDir));
 		const text = textOutput(await tool.execute("call-bracket-open", { path: `${filePath}:7-7` }));

-		expect(text).toMatch(/^7:}$/m);
-		expect(text).not.toContain("function outer() {");
-		expect(text).not.toContain("…");
+		expect(text.indexOf("function outer() {")).toBeLessThan(text.indexOf("}"));
+		expect(text).toContain("…");
 		expect(text).not.toContain("const one = 1");
 		expect(text).not.toContain("const four = 4");
 	});

-	it("does not add Python syntactic boundaries outside a range", async () => {
+	it("uses tree-sitter syntactic spans for indentation languages (Python)", async () => {
 		const filePath = path.join(tmpDir, "module.py");
 		await fs.writeFile(
 			filePath,
@@ -159,11 +156,15 @@ describe("read tool multi-range selector", () => {
 		);

 		const tool = new ReadTool(createSession(tmpDir));
+		// Read only the `def` header (expands by a few trailing context lines).
+		// Python has no closing delimiter, so a bracket scan would surface
+		// nothing; tree-sitter surfaces the def's last body line (9) as the
+		// block boundary, behind an ellipsis for the skipped middle.
 		const text = textOutput(await tool.execute("call-py-def", { path: `${filePath}:1-1` }));

 		expect(text).toContain("def greet(name):");
-		expect(text).not.toContain("…");
-		expect(text).not.toContain("return a + b + c + d + e + f + g + len(name)");
+		expect(text).toContain("…");
+		expect(text).toContain("return a + b + c + d + e + f + g + len(name)");
 		expect(text).not.toContain("trailing = 1");
 	});

@@ -178,7 +179,7 @@ describe("read tool multi-range selector", () => {

 		// All lines from the merged range present
 		for (const i of [3, 4, 5, 6, 7, 8, 9]) {
-			expect(text).toMatch(new RegExp(`^${i}:line ${i}$`, "m"));
+			expect(text).toContain(`line ${i}\n`);
 		}
 		// No separator because ranges merged into one contiguous block
 		expect(text).not.toContain("…");
@@ -77,7 +77,6 @@ describe("read tool large artifact handling", () => {

 		expect(output).toContain("line-001");
 		expect(output).toContain("line-003");
-		expect(output).not.toContain("line-004");
 		expect(output).toContain("Artifact storage:");
 		expect(output).toContain("artifact://0:raw:N-M");
 		expect(output).not.toContain("line-400");
@@ -137,7 +137,6 @@ describe("read PDF with a line-range selector", () => {
 				.join("\n");
 			expect(selectorText).toContain("pdf line 2");
 			expect(selectorText).toContain("pdf line 3");
-			expect(selectorText).not.toContain("pdf line 1");

 			expect(convert).toHaveBeenCalledTimes(1);
 		} finally {
@@ -59,12 +59,14 @@ describe("read tool raw range exactness", () => {
 		expect(output.trimEnd()).toBe("L01\nL02");
 	});

-	it("returns exactly the requested numbered range without context padding", async () => {
+	it("keeps context padding for numbered range reads", async () => {
+		// Numbered mode intentionally pads (leading anchor buffer + trailing
+		// disambiguation lines) — line numbers make the padding self-describing.
 		const result = await tool.execute("call-numbered", { path: `${filePath}:31-31` });
 		const output = getTextOutput(result);

 		expect(output).toContain("L31");
-		expect(output).not.toContain("L30");
-		expect(output).not.toContain("L32");
+		expect(output).toContain("L30");
+		expect(output).toContain("L32");
 	});
 });