fix: track body truncation explicitly instead of inferring from cap l…

src/app/api/issue/[owner]/[name]/[number]/route.ts

@@ -72,14 +72,19 @@ export async function GET(
   const db = getDb();
   const cached = db
     .prepare(
-      `SELECT id, repo_full_name, number, title, body, state, state_reason,
+      `SELECT id, repo_full_name, number, title, body, body_truncated, state, state_reason,
               author_login, author_association, labels, comments,
               created_at, updated_at, closed_at, html_url, fetched_at, first_seen_at
        FROM issues WHERE repo_full_name = ? AND number = ?`
     )
     .get(repoFullName, num) as IssueRow | undefined;
 
-  if (cached && cached.body !== null && cached.body.length !== 8000) {
+  // Serve from cache only when the stored body is complete. Truncation is read
+  // from the explicit flag the poller sets, not inferred from the body length
+  // (issue #165) — so a body that happens to equal the cap is no longer
+  // re-fetched forever, and a full body stored by an earlier detail open keeps
+  // being served instead of triggering a fresh GitHub call every poll cycle.
+  if (cached && cached.body !== null && !cached.body_truncated) {
     return NextResponse.json(
       issueRowPayload(cached, 'cache', mergedPullCountForIssue(db, repoFullName, num)),
       { headers: NO_STORE_HEADERS },
@@ -106,13 +111,16 @@ export async function GET(
 
     db.prepare(
       `INSERT INTO issues
-       (repo_full_name, number, title, body, state, state_reason, author_login, author_association,
+       (repo_full_name, number, title, body, body_truncated, state, state_reason, author_login, author_association,
         labels, comments, created_at, updated_at, closed_at, html_url, raw_json, fetched_at, first_seen_at)
-       VALUES (@repo_full_name, @number, @title, @body, @state, @state_reason, @author_login, @author_association,
+       VALUES (@repo_full_name, @number, @title, @body, 0, @state, @state_reason, @author_login, @author_association,
                @labels, @comments, @created_at, @updated_at, @closed_at, @html_url, NULL, @fetched_at, @first_seen_at)
        ON CONFLICT(repo_full_name, number) DO UPDATE SET
          title              = excluded.title,
+         -- Detail fetch returns the full, uncapped body — store it verbatim and
+         -- clear the truncated flag so the poller won't clobber it (issue #165).
          body               = excluded.body,
+         body_truncated     = 0,
          state              = excluded.state,
          state_reason       = excluded.state_reason,
          author_login       = excluded.author_login,
@@ -149,6 +157,7 @@ export async function GET(
       number: data.number,
       title: data.title,
       body: data.body ?? null,
+      body_truncated: 0,
       state: data.state,
       state_reason: data.state_reason ?? null,
       author_login: data.user?.login ?? null,

src/app/api/pull/[owner]/[name]/[number]/route.ts

@@ -35,14 +35,16 @@ export async function GET(
   const db = getDb();
   const cached = db
     .prepare(
-      `SELECT id, repo_full_name, number, title, body, state, draft, merged,
+      `SELECT id, repo_full_name, number, title, body, body_truncated, state, draft, merged,
               author_login, author_association, created_at, updated_at, closed_at, merged_at,
               html_url, fetched_at, first_seen_at
        FROM pulls WHERE repo_full_name = ? AND number = ?`
     )
     .get(repoFullName, num) as PullRow | undefined;
 
-  if (cached && cached.body !== null && cached.body.length !== 4000) {
+  // Serve from cache only when the stored body is complete, read from the
+  // explicit poller-set flag rather than inferred from length (issue #165).
+  if (cached && cached.body !== null && !cached.body_truncated) {
     return NextResponse.json({ ...cached, source: 'cache' }, { headers: NO_STORE_HEADERS });
   }
 
@@ -60,13 +62,16 @@ export async function GET(
 
     db.prepare(
       `INSERT INTO pulls
-       (repo_full_name, number, title, body, state, draft, merged, author_login, author_association,
+       (repo_full_name, number, title, body, body_truncated, state, draft, merged, author_login, author_association,
         created_at, updated_at, closed_at, merged_at, html_url, raw_json, fetched_at, first_seen_at)
-       VALUES (@repo_full_name, @number, @title, @body, @state, @draft, @merged, @author_login, @author_association,
+       VALUES (@repo_full_name, @number, @title, @body, 0, @state, @draft, @merged, @author_login, @author_association,
                @created_at, @updated_at, @closed_at, @merged_at, @html_url, NULL, @fetched_at, @first_seen_at)
        ON CONFLICT(repo_full_name, number) DO UPDATE SET
          title              = excluded.title,
+         -- Detail fetch returns the full, uncapped body — store it verbatim and
+         -- clear the truncated flag so the poller won't clobber it (issue #165).
          body               = excluded.body,
+         body_truncated     = 0,
          state              = excluded.state,
          draft              = excluded.draft,
          merged             = excluded.merged,
@@ -103,6 +108,7 @@ export async function GET(
       number: data.number,
       title: data.title,
       body: data.body ?? null,
+      body_truncated: 0,
       state: data.state,
       draft: data.draft ? 1 : 0,
       merged: data.merged ? 1 : 0,

src/app/api/related-issues/[owner]/[name]/[number]/route.ts

@@ -53,7 +53,7 @@ function selectPull(repoFullName: string, prNumber: number): PullRow | null {
   return (
     (getDb()
       .prepare(
-        `SELECT id, repo_full_name, number, title, body, state, draft, merged,
+        `SELECT id, repo_full_name, number, title, body, body_truncated, state, draft, merged,
                 author_login, author_association, created_at, updated_at, closed_at, merged_at,
                 html_url, fetched_at, first_seen_at
          FROM pulls WHERE repo_full_name = ? AND number = ?`
@@ -80,6 +80,7 @@ async function fetchPull(owner: string, repo: string, prNumber: number): Promise
       number: data.number,
       title: data.title,
       body: data.body ?? null,
+      body_truncated: 0,
       state: data.state,
       draft: data.draft ? 1 : 0,
       merged: data.merged ? 1 : 0,
@@ -122,13 +123,16 @@ async function fetchAndCacheIssue(owner: string, repo: string, issueNumber: numb
   const now = new Date().toISOString();
   db.prepare(
     `INSERT INTO issues
-     (repo_full_name, number, title, body, state, state_reason, author_login, author_association,
+     (repo_full_name, number, title, body, body_truncated, state, state_reason, author_login, author_association,
       labels, comments, created_at, updated_at, closed_at, html_url, raw_json, fetched_at, first_seen_at)
-     VALUES (@repo_full_name, @number, @title, @body, @state, @state_reason, @author_login, @author_association,
+     VALUES (@repo_full_name, @number, @title, @body, 0, @state, @state_reason, @author_login, @author_association,
              @labels, @comments, @created_at, @updated_at, @closed_at, @html_url, NULL, @fetched_at, @first_seen_at)
      ON CONFLICT(repo_full_name, number) DO UPDATE SET
        title              = excluded.title,
+       -- Full, uncapped body from issues.get — store it and clear the truncated
+       -- flag so the poller won't re-clip it (issue #165).
        body               = excluded.body,
+       body_truncated     = 0,
        state              = excluded.state,
        state_reason       = excluded.state_reason,
        author_login       = excluded.author_login,
@@ -162,7 +166,7 @@ async function fetchAndCacheIssue(owner: string, repo: string, issueNumber: numb
 function selectLinkedIssues(repoFullName: string, prNumber: number): IssueRow[] {
   return getDb()
     .prepare(
-      `SELECT i.id, i.repo_full_name, i.number, i.title, i.body, i.state, i.state_reason,
+      `SELECT i.id, i.repo_full_name, i.number, i.title, i.body, i.body_truncated, i.state, i.state_reason,
               i.author_login, i.author_association, i.labels, i.comments,
               i.created_at, i.updated_at, i.closed_at, i.html_url, i.fetched_at, i.first_seen_at
        FROM pr_issue_links l
@@ -176,7 +180,7 @@ function selectLinkedIssues(repoFullName: string, prNumber: number): IssueRow[]
 function selectRelatedPulls(repoFullName: string, issueNumber: number): PullRow[] {
   return getDb()
     .prepare(
-      `SELECT p.id, p.repo_full_name, p.number, p.title, p.body, p.state, p.draft, p.merged,
+      `SELECT p.id, p.repo_full_name, p.number, p.title, p.body, p.body_truncated, p.state, p.draft, p.merged,
               p.author_login, p.author_association, p.created_at, p.updated_at, p.closed_at, p.merged_at,
               p.html_url, p.fetched_at, p.first_seen_at
        FROM pr_issue_links l

src/lib/body-cap.ts

@@ -0,0 +1,33 @@
+// Single source of truth for how long issue/PR bodies are stored in the list
+// cache. The poller (refresh.ts) caps bodies to these lengths to bound DB size
+// across the thousands of rows it sweeps; detail opens fetch the full,
+// uncapped body and persist it.
+//
+// Whether a stored body was actually shortened is tracked explicitly via the
+// `body_truncated` flag on the `issues`/`pulls` rows — never inferred by
+// comparing the stored length to one of these constants. That inference was
+// fragile (issue #165): a body whose real length happened to equal the cap was
+// misclassified as truncated forever, and the two sides could silently drift if
+// only one cap changed. Keeping the caps here, and the truncation decision in
+// `capBody`, means the poller and the detail routes can never disagree.
+export const ISSUE_BODY_CAP = 8000;
+export const PULL_BODY_CAP = 4000;
+
+export interface CappedBody {
+  /** The body clamped to at most `cap` characters. Never null. */
+  body: string;
+  /** 1 if the original body was longer than `cap` and got shortened, else 0. */
+  truncated: 0 | 1;
+}
+
+/**
+ * Cap a body to `cap` characters, reporting whether it was actually shortened.
+ *
+ * A body whose length is exactly `cap` is NOT truncated (`slice(0, cap)` of it
+ * is the whole string) — the strict `>` is what fixes the exact-length
+ * misclassification from issue #165.
+ */
+export function capBody(body: string | null | undefined, cap: number): CappedBody {
+  const full = body ?? '';
+  return { body: full.slice(0, cap), truncated: full.length > cap ? 1 : 0 };
+}

src/lib/db.ts

@@ -1,6 +1,7 @@
 import path from 'path';
 import fs from 'fs';
 import Database from 'better-sqlite3';
+import { ISSUE_BODY_CAP, PULL_BODY_CAP } from './body-cap';
 
 const DATA_DIR = path.resolve(process.cwd(), 'data');
 if (!fs.existsSync(DATA_DIR)) fs.mkdirSync(DATA_DIR, { recursive: true });
@@ -113,6 +114,7 @@ export function getDb(): Database.Database {
       number             INTEGER NOT NULL,
       title              TEXT NOT NULL,
       body               TEXT,
+      body_truncated     INTEGER NOT NULL DEFAULT 0,
       state              TEXT NOT NULL,
       state_reason       TEXT,
       author_login       TEXT,
@@ -145,6 +147,7 @@ export function getDb(): Database.Database {
       number             INTEGER NOT NULL,
       title              TEXT NOT NULL,
       body               TEXT,
+      body_truncated     INTEGER NOT NULL DEFAULT 0,
       state              TEXT NOT NULL,
       draft              INTEGER DEFAULT 0,
       merged             INTEGER DEFAULT 0,
@@ -311,6 +314,33 @@ export function getDb(): Database.Database {
     db.exec('ALTER TABLE pulls ADD COLUMN author_association TEXT');
   }
 
+  // `body_truncated` (issue #165) records whether a stored body was capped by
+  // the poller, replacing the old "stored length == cap" inference in the
+  // detail routes. When the column is first added we backfill it: a poller-
+  // capped body lands at exactly the cap length, so flag those rows truncated.
+  // Erring toward `1` is the safe direction — a false truncated flag costs one
+  // detail re-fetch that then re-stores the full body and self-heals the flag,
+  // whereas a false complete flag would serve a clipped body as if whole.
+  // The ADD COLUMN and its backfill must commit together: if a crash landed
+  // between them, the next boot would see the column present, skip this block,
+  // and leave capped rows defaulted to 0 (complete) — the unsafe direction.
+  // Wrapping in a transaction rolls the ALTER back too, so the migration re-runs.
+  const issuesCols = db.prepare("PRAGMA table_info(issues)").all() as Array<{ name: string }>;
+  if (!issuesCols.some((c) => c.name === 'body_truncated')) {
+    db.transaction(() => {
+      db.exec('ALTER TABLE issues ADD COLUMN body_truncated INTEGER NOT NULL DEFAULT 0');
+      db.prepare('UPDATE issues SET body_truncated = 1 WHERE body IS NOT NULL AND length(body) = ?')
+        .run(ISSUE_BODY_CAP);
+    })();
+  }
+  if (!pullsCols.some((c) => c.name === 'body_truncated')) {
+    db.transaction(() => {
+      db.exec('ALTER TABLE pulls ADD COLUMN body_truncated INTEGER NOT NULL DEFAULT 0');
+      db.prepare('UPDATE pulls SET body_truncated = 1 WHERE body IS NOT NULL AND length(body) = ?')
+        .run(PULL_BODY_CAP);
+    })();
+  }
+
   // One-shot purge of false-positive pr_issue_links (issue #137). Guarded by
   // PRAGMA user_version so it runs exactly once per database file.
   const schemaVersion = (db.prepare('PRAGMA user_version').get() as { user_version: number }).user_version;
@@ -332,6 +362,7 @@ export interface IssueRow {
   number: number;
   title: string;
   body: string | null;
+  body_truncated: number;
   state: string;
   state_reason: string | null;
   author_login: string | null;
@@ -352,6 +383,7 @@ export interface PullRow {
   number: number;
   title: string;
   body: string | null;
+  body_truncated: number;
   state: string;
   draft: number;
   merged: number;

src/lib/refresh.ts

@@ -11,6 +11,7 @@ import {
   withRotation,
 } from './github';
 import { extractLinkedIssues } from './pr-linking';
+import { ISSUE_BODY_CAP, PULL_BODY_CAP, capBody } from './body-cap';
 
 /**
  * Add this PR's `pr_issue_links` rows from the body+title regex. Only
@@ -458,15 +459,32 @@ function upsertIssue(repoFullName: string, issue: GhIssue): void {
 
   const firstSeen = existing?.first_seen_at ?? nowIso();
 
+  const { body: cappedBody, truncated } = capBody(issue.body, ISSUE_BODY_CAP);
   db.prepare(
     `INSERT INTO issues
-     (repo_full_name, number, title, body, state, state_reason, author_login, author_association,
+     (repo_full_name, number, title, body, body_truncated, state, state_reason, author_login, author_association,
       labels, comments, created_at, updated_at, closed_at, html_url, raw_json, fetched_at, first_seen_at)
-     VALUES (@repo_full_name, @number, @title, @body, @state, @state_reason, @author_login, @author_association,
+     VALUES (@repo_full_name, @number, @title, @body, @body_truncated, @state, @state_reason, @author_login, @author_association,
              @labels, @comments, @created_at, @updated_at, @closed_at, @html_url, NULL, @fetched_at, @first_seen_at)
      ON CONFLICT(repo_full_name, number) DO UPDATE SET
        title              = excluded.title,
-       body               = excluded.body,
+       -- Don't let a poller sweep downgrade a complete body (e.g. one a detail
+       -- open fetched in full) back to a capped slice (issue #165). Overwrite
+       -- only when the incoming body is itself complete, the stored body is
+       -- already truncated, or the incoming text is at least as long as what's
+       -- stored (so a genuinely grown body still wins). A rarely-edited long
+       -- body may go briefly stale here; that's the accepted trade for keeping
+       -- the detail cache warm.
+       body               = CASE
+         WHEN excluded.body_truncated = 0
+           OR issues.body_truncated = 1
+           OR length(excluded.body) >= length(IFNULL(issues.body, ''))
+         THEN excluded.body ELSE issues.body END,
+       body_truncated     = CASE
+         WHEN excluded.body_truncated = 0
+           OR issues.body_truncated = 1
+           OR length(excluded.body) >= length(IFNULL(issues.body, ''))
+         THEN excluded.body_truncated ELSE issues.body_truncated END,
        state              = excluded.state,
        state_reason       = excluded.state_reason,
        author_login       = excluded.author_login,
@@ -482,7 +500,8 @@ function upsertIssue(repoFullName: string, issue: GhIssue): void {
     repo_full_name: repoFullName,
     number: issue.number,
     title: issue.title,
-    body: (issue.body ?? '').slice(0, 8000),
+    body: cappedBody,
+    body_truncated: truncated,
     state: issue.state,
     state_reason: issue.state_reason,
     author_login: issue.user?.login ?? null,
@@ -507,16 +526,27 @@ function upsertPull(repoFullName: string, pull: GhPull): void {
   const firstSeen = existing?.first_seen_at ?? nowIso();
   const merged = pull.merged_at ? 1 : 0;
 
-  const truncatedBody = (pull.body ?? '').slice(0, 4000);
+  const { body: truncatedBody, truncated } = capBody(pull.body, PULL_BODY_CAP);
   db.prepare(
     `INSERT INTO pulls
-     (repo_full_name, number, title, body, state, draft, merged, author_login, author_association,
+     (repo_full_name, number, title, body, body_truncated, state, draft, merged, author_login, author_association,
       created_at, updated_at, closed_at, merged_at, html_url, raw_json, fetched_at, first_seen_at)
-     VALUES (@repo_full_name, @number, @title, @body, @state, @draft, @merged, @author_login, @author_association,
+     VALUES (@repo_full_name, @number, @title, @body, @body_truncated, @state, @draft, @merged, @author_login, @author_association,
              @created_at, @updated_at, @closed_at, @merged_at, @html_url, NULL, @fetched_at, @first_seen_at)
      ON CONFLICT(repo_full_name, number) DO UPDATE SET
        title              = excluded.title,
-       body               = excluded.body,
+       -- See upsertIssue: never downgrade a complete body to a capped slice on
+       -- a poller sweep (issue #165).
+       body               = CASE
+         WHEN excluded.body_truncated = 0
+           OR pulls.body_truncated = 1
+           OR length(excluded.body) >= length(IFNULL(pulls.body, ''))
+         THEN excluded.body ELSE pulls.body END,
+       body_truncated     = CASE
+         WHEN excluded.body_truncated = 0
+           OR pulls.body_truncated = 1
+           OR length(excluded.body) >= length(IFNULL(pulls.body, ''))
+         THEN excluded.body_truncated ELSE pulls.body_truncated END,
        state              = excluded.state,
        draft              = excluded.draft,
        merged             = excluded.merged,
@@ -531,6 +561,7 @@ function upsertPull(repoFullName: string, pull: GhPull): void {
     number: pull.number,
     title: pull.title,
     body: truncatedBody,
+    body_truncated: truncated,
     state: pull.state,
     draft: pull.draft ? 1 : 0,
     merged,