From 902804cf2fd78e18b4e2ae4e7d13ad6e3800c25f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani.haverinen@gmail.com>
Date: Sat, 26 May 2018 22:33:55 +0300
Subject: [PATCH] Make the memory dump in ircbotRun() better at determining
 tape head location

---
 gir.js | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/gir.js b/gir.js
index bd2b3d8..80893c5 100644
--- a/gir.js
+++ b/gir.js
@@ -403,6 +403,17 @@ function addOffsetProperties(parsed) {
 				offsetted.push({type: readInt,
 					offset: offset});
 			} else if(command.type == breakPoint) {
+				// A breakpoint should have the tape head
+				// where it would be without the offsets
+				// If offset is not 0, add a moveHead
+				if(offset != 0) {
+					offsetted.push({type: moveHead,
+						value: offset});
+					// Mark we've moved the head
+					headChange += offset;
+				}
+				offset = 0;
+
 				// Add the breakpoint
 				offsetted.push({type: breakPoint});
 			} else {
@@ -926,6 +937,10 @@ function ircbotRun(program, input, maxCycles = 400000) {
 	let result = runVM(vm, maxCycles);
 	let output = decodeUTF8(result.state.output);
 
+	// Did we run into maxCycles?
+	let executedTooLong = maxCycles != null &&
+		result.cycles >= maxCycles;
+
 	// If there was either no output or a breakpoint triggered, dump
 	// tape to output instead
 	if(output.length == 0 || result.breakPointReached) {
@@ -935,10 +950,12 @@ function ircbotRun(program, input, maxCycles = 400000) {
 		}
 
 		// Get the tape head we should have here
-		// Since commands in the virtual machine can act at offsets,
-		// what we want is the last offset accessed, unless that is
-		// null
-		let tapeHead = result.lastIndex || result.state.tapeHead;
+		// Both the program completing succesfully and a breakpoint
+		// will leave the tape head "where it should be". The cycle
+		// limit can however stop a program at any point. Therefore
+		// in such cases more useful is the last index that was
+		// accessed
+		let tapeHead = executedTooLong ? result.lastIndex : result.state.tapeHead;
 
 		// Find min and max of the existant array indinces, since
 		// there is no good way to easily get them and we need them
@@ -993,8 +1010,8 @@ function ircbotRun(program, input, maxCycles = 400000) {
 		output += `{${min}…${max}}(${start > min ? '… ' : ''}${cells.join(' ')}${end < max ? ' …' : ''})`
 	}
 
-	// Did we run into maxCycles?
-	if(maxCycles != null && result.cycles >= maxCycles) {
+	// Add «TLE» to signify execution taking too long
+	if(executedTooLong) {
 		output += '«TLE»';
 	}