diff --git a/src/hooks/anthropic-context-window-limit-recovery/parser.ts b/src/hooks/anthropic-context-window-limit-recovery/parser.ts
index 451d1ab18..24483e0fa 100644
--- a/src/hooks/anthropic-context-window-limit-recovery/parser.ts
+++ b/src/hooks/anthropic-context-window-limit-recovery/parser.ts
@@ -70,7 +70,7 @@ function isTokenLimitError(text: string): boolean {
     return false
   }
   const lower = text.toLowerCase()
-  return TOKEN_LIMIT_KEYWORDS.some((kw) => lower.includes(kw.toLowerCase()))
+  return TOKEN_LIMIT_KEYWORDS.some((kw) => lower.includes(kw))
 }
 
 export function parseAnthropicTokenLimitError(err: unknown): ParsedTokenLimitError | null {
diff --git a/src/hooks/runtime-fallback/error-classifier.ts b/src/hooks/runtime-fallback/error-classifier.ts
index 46d136b44..e581f3fb8 100644
--- a/src/hooks/runtime-fallback/error-classifier.ts
+++ b/src/hooks/runtime-fallback/error-classifier.ts
@@ -28,6 +28,8 @@ export function getErrorMessage(error: unknown): string {
   }
 }
 
+const DEFAULT_RETRY_PATTERN = new RegExp(`\\b(${DEFAULT_CONFIG.retry_on_errors.join("|")})\\b`)
+
 export function extractStatusCode(error: unknown, retryOnErrors?: number[]): number | undefined {
   if (!error) return undefined
 
@@ -45,8 +47,9 @@ export function extractStatusCode(error: unknown, retryOnErrors?: number[]): num
     return statusCode
   }
 
-  const codes = retryOnErrors ?? DEFAULT_CONFIG.retry_on_errors
-  const pattern = new RegExp(`\\b(${codes.join("|")})\\b`)
+  const pattern = retryOnErrors 
+    ? new RegExp(`\\b(${retryOnErrors.join("|")})\\b`)
+    : DEFAULT_RETRY_PATTERN
   const message = getErrorMessage(error)
   const statusMatch = message.match(pattern)
   if (statusMatch) {
diff --git a/src/hooks/think-mode/detector.ts b/src/hooks/think-mode/detector.ts
index 9ef7561a9..5fcd9f5c1 100644
--- a/src/hooks/think-mode/detector.ts
+++ b/src/hooks/think-mode/detector.ts
@@ -32,8 +32,10 @@ const MULTILINGUAL_KEYWORDS = [
   "fikir", "berfikir",
 ]
 
-const MULTILINGUAL_PATTERNS = MULTILINGUAL_KEYWORDS.map((kw) => new RegExp(kw, "i"))
-const THINK_PATTERNS = [...ENGLISH_PATTERNS, ...MULTILINGUAL_PATTERNS]
+const COMBINED_THINK_PATTERN = new RegExp(
+  `\\b(?:ultrathink|think)\\b|${MULTILINGUAL_KEYWORDS.join("|")}`,
+  "i"
+)
 
 const CODE_BLOCK_PATTERN = /```[\s\S]*?```/g
 const INLINE_CODE_PATTERN = /`[^`]+`/g
@@ -44,7 +46,7 @@ function removeCodeBlocks(text: string): string {
 
 export function detectThinkKeyword(text: string): boolean {
   const textWithoutCode = removeCodeBlocks(text)
-  return THINK_PATTERNS.some((pattern) => pattern.test(textWithoutCode))
+  return COMBINED_THINK_PATTERN.test(textWithoutCode)
 }
 
 export function extractPromptText(
diff --git a/src/tools/hashline-edit/edit-operations.ts b/src/tools/hashline-edit/edit-operations.ts
index caec23071..13b010f95 100644
--- a/src/tools/hashline-edit/edit-operations.ts
+++ b/src/tools/hashline-edit/edit-operations.ts
@@ -11,6 +11,14 @@ import {
 } from "./edit-operation-primitives"
 import { validateLineRefs } from "./validation"
 
+function arraysEqual(a: string[], b: string[]): boolean {
+  if (a.length !== b.length) return false
+  for (let i = 0; i < a.length; i++) {
+    if (a[i] !== b[i]) return false
+  }
+  return true
+}
+
 export interface HashlineApplyReport {
   content: string
   noopEdits: number
@@ -51,7 +59,7 @@ export function applyHashlineEditsWithReport(content: string, edits: HashlineEdi
         const next = edit.end
           ? applyReplaceLines(lines, edit.pos, edit.end, edit.lines, { skipValidation: true })
           : applySetLine(lines, edit.pos, edit.lines, { skipValidation: true })
-        if (next.join("\n") === lines.join("\n")) {
+        if (arraysEqual(next, lines)) {
           noopEdits += 1
           break
         }
@@ -62,7 +70,7 @@ export function applyHashlineEditsWithReport(content: string, edits: HashlineEdi
         const next = edit.pos
           ? applyInsertAfter(lines, edit.pos, edit.lines, { skipValidation: true })
           : applyAppend(lines, edit.lines)
-        if (next.join("\n") === lines.join("\n")) {
+        if (arraysEqual(next, lines)) {
           noopEdits += 1
           break
         }
@@ -73,7 +81,7 @@ export function applyHashlineEditsWithReport(content: string, edits: HashlineEdi
         const next = edit.pos
           ? applyInsertBefore(lines, edit.pos, edit.lines, { skipValidation: true })
           : applyPrepend(lines, edit.lines)
-        if (next.join("\n") === lines.join("\n")) {
+        if (arraysEqual(next, lines)) {
           noopEdits += 1
           break
         }
diff --git a/src/tools/hashline-edit/hash-computation.ts b/src/tools/hashline-edit/hash-computation.ts
index ac8d3f55c..a6bf8da78 100644
--- a/src/tools/hashline-edit/hash-computation.ts
+++ b/src/tools/hashline-edit/hash-computation.ts
@@ -86,15 +86,17 @@ export async function* streamHashLinesFromUtf8(
     pending += text
     const chunksToYield: string[] = []
 
+    let lastIdx = 0
     while (true) {
-      const idx = pending.indexOf("\n")
+      const idx = pending.indexOf("\n", lastIdx)
       if (idx === -1) break
-      const line = pending.slice(0, idx)
-      pending = pending.slice(idx + 1)
+      const line = pending.slice(lastIdx, idx)
+      lastIdx = idx + 1
       endedWithNewline = true
       chunksToYield.push(...pushLine(line))
     }
 
+    pending = pending.slice(lastIdx)
     if (pending.length > 0) endedWithNewline = false
     return chunksToYield
   }