1 files changed, 27 insertions, 9 deletions
diff --git a/modules/test/test-pipe-guard.js b/modules/test/test-pipe-guard.js
index 0bd7cc9..7851613 100644
--- a/modules/test/test-pipe-guard.js
+++ b/modules/test/test-pipe-guard.js
@@ -1,8 +1,13 @@
 // modules/test/test-pipe-guard.js — run: node modules/test/test-pipe-guard.js
-// Fails fast if either guard is removed or if a guard is placed AFTER the parts[0] read.
-// Behavioural proof is the browser matrix (plan Task 8); this test is the cheap tripwire.
+// Cheap tripwire for the three things that silently broke pipe handling before:
+//   1. _parseArgs('') returning a non-empty argv (parts[0] === undefined -> TypeError, 989 hits)
+//   2. the empty-stage guard being placed AFTER the parts[0] read
+//   3. v4.6.131: the raw stage text being discarded, in BOTH pipe implementations — the core one
+//      and the ShellModule override that actually replaces it at boot (measured 2026-10-29:
+//      terminal.executePipeChain.toString() contained `cmdText.split`, not `lastStage`).
 const fs = require('fs'), path = require('path');
 const src = fs.readFileSync(path.join(__dirname, '../core/terminal.js'), 'utf8');
+const shellSrc = fs.readFileSync(path.join(__dirname, '../ext/shell.js'), 'utf8');
 
 // 1. _parseArgs('') must return [] — that precondition is what made parts[0] undefined.
 // The source is a CLASS METHOD, so wrap it in an object literal (a bare `new Function('m(){…}')`
@@ -19,16 +24,29 @@ const cGuard = src.indexOf('if (!parts.length)', ci);
 const cRead = src.indexOf('parts[0].toLowerCase()', ci);
 const classifyGuarded = ci >= 0 && cGuard > ci && cGuard < cRead;
 
+// 3. core executePipeChain: skip empty stages without shifting the index (v4.6.131 replaced the
+//    `.filter(argv => argv.length > 0)` with a lastStage scan so stages[i] stays aligned with
+//    pipeParts[i]), and forward each stage's raw text to the dispatcher.
 const pi = src.indexOf('async executePipeChain(');
-const pGuard = src.indexOf('if (!stages.length)', pi);
-const pFilter = src.indexOf('.filter(argv => argv.length > 0)', pi);
-const pRead = src.indexOf('argv[0].toLowerCase()', pi);
-const pipeGuarded = pi >= 0 && pFilter > pi && pGuard > pFilter && pRead > pGuard
-    && src.indexOf('i < stages.length - 1', pi) > 0;
+const body = pi >= 0 ? src.slice(pi, src.indexOf('async capturePipeOutput(', pi)) : '';
+const pEmpty = body.indexOf('if (lastStage < 0)');
+const pSkip = body.indexOf('if (argv.length === 0) continue');
+const pRead = body.indexOf('argv[0].toLowerCase()');
+const pRaw = body.indexOf('dispatchCommand(cmd, args, pipeParts[i])');
+const pipeGuarded = pi >= 0 && pEmpty > 0 && pSkip > pEmpty && pRead > pSkip && pRaw > pRead
+    && body.indexOf('this.capturePipeOutput(cmd, args, pipeParts[i])') > 0;
 
-const report = { empty, blank, classifyGuarded, pipeGuarded };
+// 4. the override that actually runs: ShellModule.init() replaces terminal.executePipeChain, so a
+//    fix in the core alone is dead code. Measured live: the wrapper is the shell's.
+const si = shellSrc.indexOf('this.terminal.executePipeChain = async function(pipeParts)');
+const shellBody = si >= 0 ? shellSrc.slice(si, shellSrc.indexOf('_splitSequence(', si)) : '';
+const shellForwardsRaw = si >= 0
+    && shellBody.indexOf('this.dispatchCommand(cmd, args, cmdText)') > 0
+    && shellBody.indexOf('this.capturePipeOutput(cmd, args, cmdText)') > 0;
+
+const report = { empty, blank, classifyGuarded, pipeGuarded, shellForwardsRaw };
 console.log(JSON.stringify(report));
 const ok = Array.isArray(empty) && empty.length === 0
     && Array.isArray(blank) && blank.length === 0
-    && classifyGuarded && pipeGuarded;
+    && classifyGuarded && pipeGuarded && shellForwardsRaw;
 process.exit(ok ? 0 : 1);