Merge pull request #1441 from ispyisail/fix/f101-link-order

Fix a coil's contacts being saved in a different order each time

sources/qetgraphicsitem/element.cpp

@@ -1642,6 +1642,7 @@ void Element::initLink(QETProject *prj)
 			}
 		}
 	}
+	restoreSavedLinkOrder();
 	tmp_uuids_link.clear();
 }
 
@@ -1669,9 +1670,36 @@ void Element::initLink(const QList<Element *> &candidates)
 			}
 		}
 	}
+	restoreSavedLinkOrder();
 	tmp_uuids_link.clear();
 }
 
+/**
+	@brief Element::restoreSavedLinkOrder
+	Put connected_elements back in the order tmp_uuids_link saved them.
+	Partners link in the order the folios' items are visited, and for
+	items at the same height that order changes from run to run, so a
+	master's contacts were saved in a different order each time.
+	Linked elements missing from the saved list keep their place after it.
+*/
+void Element::restoreSavedLinkOrder()
+{
+	QList<Element *> ordered;
+	for (const auto &link_info : std::as_const(tmp_uuids_link)) {
+		for (Element *elmt : std::as_const(connected_elements)) {
+			if (elmt->uuid() == link_info.uuid && !ordered.contains(elmt)) {
+				ordered << elmt;
+				break;
+			}
+		}
+	}
+	for (Element *elmt : std::as_const(connected_elements)) {
+		if (!ordered.contains(elmt))
+			ordered << elmt;
+	}
+	connected_elements = ordered;
+}
+
 /**
  * @brief Element::linkTypeToString
  * \deprecated use instead ElementData::typeToString

sources/qetgraphicsitem/element.h

@@ -328,6 +328,7 @@ class Element : public QetGraphicsItem
 		QList<QPointF> plcTablePositions() const { return m_plc_table_positions; }
 
 	private:
+		void restoreSavedLinkOrder();
 		bool m_must_highlight = false;
 		QSize   dimensions;
 		QPoint  hotspot_coord;

tests/qttest/tst_resaveunchanged.cpp

@@ -19,7 +19,8 @@
 //    was opened again (m_000.qet).
 // Runs the real binary's --resave twice on every example, on a project
 // whose title block holds a value that is a single space (#973), and on
-// one that used to crash on opening (bugtracker #345).
+// one that used to crash on opening (bugtracker #345); and that a coil's
+// contacts keep the order the file saved them in.
 class tst_resaveunchanged : public QObject
 {
 	Q_OBJECT
@@ -118,6 +119,47 @@ private slots:
 				 "a machine manufacturer reference variable was left unresolved");
 	}
 
+	// A coil's contacts are saved in the order the file listed them.
+	// They used to come back in the order the folios were visited, so a
+	// list that disagreed with it changed on every save, and contacts on
+	// one folio swapped places from run to run. m_000.qet's coil b02216df
+	// (folio 13) lists its contacts on folios 7 and 12; the test lists
+	// them the other way round.
+	void savedLinkOrderKept()
+	{
+		QByteArray xml = read(QStringLiteral(QET_EXAMPLES_DIR "/m_000.qet"));
+		const QRegularExpression coil(QStringLiteral(
+				"<element [^>]*uuid=\"\\{b02216df-0851-4732-893b-901fea80703e\\}\""));
+		// byte offset of the coil's <element> tag in @p file, or -1
+		const auto coilAt = [&coil](const QByteArray &file) {
+			const QRegularExpressionMatch m = coil.match(QString::fromLatin1(file));
+			return m.hasMatch() ? int(m.capturedStart()) : -1;
+		};
+		const QByteArray a = "<link_uuid uuid=\"{998190fa-5b4c-4be3-bc67-8a828eaab2b4}\"/>";
+		const QByteArray b = "<link_uuid uuid=\"{112aa911-",
+				b_end = "\"/>";
+		const int start = coilAt(xml);
+		QVERIFY(start > 0);
+		const int ia = xml.indexOf(a, start), ib = xml.indexOf(b, start);
+		QVERIFY2(ia > 0 && ib > ia, "m_000.qet no longer lists the coil's contacts as expected");
+		const QByteArray link_b = xml.mid(ib, xml.indexOf(b_end, ib) + b_end.size() - ib);
+		xml.replace(ib, link_b.size(), a);
+		xml.replace(ia, a.size(), link_b);
+		const QString in = m_dir.filePath(QStringLiteral("links.qet"));
+		QFile f(in);
+		QVERIFY(f.open(QIODevice::WriteOnly));
+		f.write(xml);
+		f.close();
+
+		const QByteArray saved = read(resave(in));
+		QVERIFY2(!saved.isEmpty(), "--resave failed");
+		const int s = coilAt(saved);
+		QVERIFY(s > 0);
+		const int sa = saved.indexOf(a, s), sb = saved.indexOf(b, s);
+		QVERIFY2(sa > 0 && sb > 0, "a link was lost");
+		QVERIFY2(sb < sa, "the coil's contacts were saved in another order than the file's");
+	}
+
 	// A title-block value that is a single space is kept through two saves
 	// (#973), and a value with accents comes back as it went in.
 	void singleSpaceValueKept()