diff --git a/sources/diagram.cpp b/sources/diagram.cpp
index 4831b6484..c0e89fdd2 100644
--- a/sources/diagram.cpp
+++ b/sources/diagram.cpp
@@ -437,6 +437,24 @@ void Diagram::mousePressEvent(QGraphicsSceneMouseEvent *event)
 	}
 
 	rememberSelection();
+		//Clicking again on a member of a group that is selected whole picks
+		//that member out, to edit it on its own (discussion #1070): noted
+		//here, decided on release, since a drag must still move the group.
+		//Ctrl keeps its usual meaning.
+	m_member_to_pick.clear();
+	if (event->button() == Qt::LeftButton
+		&& !event->modifiers().testFlag(Qt::ControlModifier)) {
+		QTransform view_transform;
+		if (event->widget()) {
+			if (auto view = qobject_cast<QGraphicsView *>(event->widget()->parentWidget())) {
+				view_transform = view->transform();
+			}
+		}
+		if (QGraphicsItem *member = ItemGroups::memberToPick(
+				itemAt(event->scenePos(), view_transform))) {
+			m_member_to_pick = member->toGraphicsObject();
+		}
+	}
 	QGraphicsScene::mousePressEvent(event);
 	completeGroupSelection();
 }
@@ -477,6 +495,19 @@ void Diagram::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 	}
 
 	QGraphicsScene::mouseReleaseEvent(event);
+
+		//A click that did not drag, on a member of a group selected whole:
+		//Qt has left only that member selected, and it stays so.
+	QGraphicsObject *picked = m_member_to_pick.data();
+	m_member_to_pick.clear();
+	if (picked
+		&& (event->screenPos() - event->buttonDownScreenPos(Qt::LeftButton)).manhattanLength()
+			< QApplication::startDragDistance()
+		&& selectedItems() == QList<QGraphicsItem *>{picked}) {
+		rememberSelection();
+		return;
+	}
+
 		//A click on an already selected item changes the selection on
 		//release, not on press (Ctrl toggles it, a plain click keeps only it).
 	completeGroupSelection();
@@ -1676,6 +1707,23 @@ bool Diagram::fromXml(QDomElement &document,
 			delete nvel_elmt;
 			qDebug() << QStringLiteral("Diagram::fromXml() : Le chargement des parametres d'un element a echoue");
 		} else {
+				//A symbol saved without a uuid got a random one from
+				//Element::fromXml(): a different identity on every load,
+				//written out on the next save. Derive it instead from what
+				//the symbol is and where it sits on its folio -- never from
+				//the folio's index, so inserting or moving a folio does not
+				//change it. Only for a folio being loaded: a paste renews
+				//uuids anyway.
+			if (consider_informations && m_project
+				&& QUuid(element_xml.attribute(QStringLiteral("uuid"))).isNull()) {
+				nvel_elmt->setUuid(m_project->derivedItemUuid(
+									   QStringLiteral("element"),
+									   QStringList{type_id,
+												   element_xml.attribute(QStringLiteral("x")),
+												   element_xml.attribute(QStringLiteral("y")),
+												   element_xml.attribute(QStringLiteral("orientation"))}
+									   .join(QLatin1Char('\n'))));
+			}
 			ItemGroups::setGroup(nvel_elmt, ItemGroups::read(element_xml));
 			added_elements << nvel_elmt;
 		}
diff --git a/sources/diagram.h b/sources/diagram.h
index 8c2b453d6..83d408835 100644
--- a/sources/diagram.h
+++ b/sources/diagram.h
@@ -142,6 +142,9 @@ class Diagram : public QGraphicsScene
 			//Selection before the current click, see completeGroupSelection()
 		QList<QPointer<QGraphicsObject>> m_previous_selection;
 		void rememberSelection();
+			//Member of a wholly selected group under the current click, which
+			//the click picks out on its own if it ends without a drag
+		QPointer<QGraphicsObject> m_member_to_pick;
 
 		bool uuidUsedByOtherDiagram(const QUuid &uuid) const;
 		QUuid derivedUuid(const QDomElement &root, const QString &reason) const;
diff --git a/sources/diagramcontext.cpp b/sources/diagramcontext.cpp
index 5137a7bf5..94b8696a2 100644
--- a/sources/diagramcontext.cpp
+++ b/sources/diagramcontext.cpp
@@ -144,6 +144,27 @@ bool DiagramContext::operator!=(const DiagramContext &dc) const
 	return(!(*this == dc));
 }
 
+namespace {
+/**
+	The value as it is saved, and so as it is read back: stray leading and
+	trailing whitespace around real content trimmed, but not a value that IS
+	whitespace -- unconditionally trimming an all-whitespace string collapses
+	it to "", which is silently indistinguishable from a value that was never
+	set. A title-block custom variable set to a single space -- a workaround
+	for #973, where an unset variable renders as its own literal placeholder
+	-- would otherwise vanish on the very next save.
+	Applied when reading as well as when writing, so that what is in memory
+	after a load is what the next save writes: a label shown from an
+	untrimmed value would otherwise keep its spaces on screen and in its
+	displayed copy until the project was saved and opened again, and a
+	just-saved project would change on its second save.
+*/
+QString storedValue(const QString &raw)
+{
+	return raw.trimmed().isEmpty() ? raw : raw.trimmed();
+}
+} // namespace
+
 /**
 	Export this context properties under the \a e XML element, using tags
 	named \a tag_name (defaults to "property").
@@ -161,15 +182,7 @@ void DiagramContext::toXml(QDomElement &e, const QString &tag_name) const
 		property.removeAttribute("name");
 		property.setAttribute("show", m_content_show[key]);
 		property.setAttribute("name", key);
-		// Trim stray leading/trailing whitespace around real content, but
-		// not a value that IS whitespace: unconditionally trimming an
-		// all-whitespace string collapses it to "", which is silently
-		// indistinguishable from a value that was never set. A title-block
-		// custom variable set to a single space -- a workaround for #973,
-		// where an unset variable renders as its own literal placeholder --
-		// would otherwise vanish on the very next save.
-		const QString stored = raw.trimmed().isEmpty() ? raw : raw.trimmed();
-		QDomText value = e.ownerDocument().createTextNode(stored);
+		QDomText value = e.ownerDocument().createTextNode(storedValue(raw));
 		property.appendChild(value);
 		e.appendChild(property);
 	}
@@ -182,7 +195,7 @@ void DiagramContext::toXml(QDomElement &e, const QString &tag_name) const
 void DiagramContext::fromXml(const QDomElement &e, const QString &tag_name) {
 	foreach (QDomElement property, QET::findInDomElement(e, tag_name)) {
 		if (!property.hasAttribute("name")) continue;
-		addValue(property.attribute("name"), QVariant(property.text()));
+		addValue(property.attribute("name"), QVariant(storedValue(property.text())));
 		m_content_show.insert(property.attribute("name"), property.attribute("show", "1").toInt());
 	}
 }
@@ -198,7 +211,8 @@ void DiagramContext::fromXml(const pugi::xml_node &dom_element, const QString &t
 {
 	for(auto node = dom_element.child(tag_name.toStdString().c_str()) ; node ; node = node.next_sibling(tag_name.toStdString().c_str()))
 	{
-		addValue(node.attribute("name").as_string(), QVariant(node.text().as_string()));
+		addValue(node.attribute("name").as_string(),
+				 QVariant(storedValue(QString::fromUtf8(node.text().as_string()))));
 		m_content_show.insert(node.attribute("name").as_string(), node.attribute("show").empty()? 1 : node.attribute("show").as_int());
 	}
 }
diff --git a/sources/itemgroups.cpp b/sources/itemgroups.cpp
index 4e4c7ac9d..8ad4c2256 100644
--- a/sources/itemgroups.cpp
+++ b/sources/itemgroups.cpp
@@ -62,6 +62,47 @@ QUuid ItemGroups::read(const QDomElement &xml)
 	return QUuid(xml.attribute(QString::fromLatin1(xml_attribute)));
 }
 
+/**
+	@return @a item, or its nearest ancestor, that belongs to a group -- a
+	click on a symbol's own text hits the text, but the symbol is the member
+	-- or nullptr if none does.
+*/
+QGraphicsItem *ItemGroups::groupedItem(QGraphicsItem *item)
+{
+	for (; item; item = item->parentItem()) {
+		if (!groupOf(item).isNull()) {
+			return item;
+		}
+	}
+	return nullptr;
+}
+
+/**
+	@return the member a click on @a hit may pick out on its own: the grouped
+	item hit, when every member of its group is selected already. A first
+	click selects the whole group; a second click, on a member of the group
+	it selected, is how the user asks for that member alone (discussion
+	#1070). nullptr when the click is not that.
+*/
+QGraphicsItem *ItemGroups::memberToPick(QGraphicsItem *hit)
+{
+	QGraphicsItem *member = groupedItem(hit);
+	if (!member || !member->isSelected() || !member->scene()) {
+		return nullptr;
+	}
+	const QUuid group = groupOf(member);
+	int members = 0;
+	for (QGraphicsItem *item : member->scene()->items()) {
+		if (groupOf(item) == group) {
+			if (!item->isSelected()) {
+				return nullptr;
+			}
+			++members;
+		}
+	}
+	return members > 1 ? member : nullptr;
+}
+
 /**
 	Make the selection of @a scene whole groups again after it changed.
 	A group with a selected member is selected entirely, except when the
@@ -122,3 +163,34 @@ bool ItemGroups::completeSelection(QGraphicsScene *scene,
 	}
 	return changed;
 }
+
+/**
+	@return the group @a selected is exactly, whole -- every item in it
+	belongs to that group and every member of the group is in it -- or a null
+	uuid. Rotating such a selection turns the group as one piece rather than
+	each member in place (discussion #1070). A member picked out on its own
+	is not a whole group, and turns in place.
+	@param selected : the selected items that can be members (the caller
+	leaves out wires, which follow their symbols)
+*/
+QUuid ItemGroups::soleWholeGroup(const QList<QGraphicsItem *> &selected)
+{
+	if (selected.isEmpty() || !selected.first()->scene()) {
+		return QUuid();
+	}
+	const QUuid group = groupOf(selected.first());
+	if (group.isNull()) {
+		return QUuid();
+	}
+	for (QGraphicsItem *item : selected) {
+		if (groupOf(item) != group) {
+			return QUuid();
+		}
+	}
+	for (QGraphicsItem *item : selected.first()->scene()->items()) {
+		if (groupOf(item) == group && !item->isSelected()) {
+			return QUuid();
+		}
+	}
+	return group;
+}
diff --git a/sources/itemgroups.h b/sources/itemgroups.h
index 7e3c944b1..90840ffbd 100644
--- a/sources/itemgroups.h
+++ b/sources/itemgroups.h
@@ -52,9 +52,14 @@ namespace ItemGroups
 	void write(QDomElement &xml, const QGraphicsItem *item);
 	QUuid read(const QDomElement &xml);
 
+	QGraphicsItem *groupedItem(QGraphicsItem *item);
+	QGraphicsItem *memberToPick(QGraphicsItem *hit);
+
 	bool completeSelection(QGraphicsScene *scene,
 						   const QList<QGraphicsItem *> &previous,
 						   bool toggling);
+
+	QUuid soleWholeGroup(const QList<QGraphicsItem *> &selected);
 }
 
 #endif // ITEMGROUPS_H
diff --git a/sources/qetdiagrameditor.cpp b/sources/qetdiagrameditor.cpp
index d65d94b95..80d52f4dd 100644
--- a/sources/qetdiagrameditor.cpp
+++ b/sources/qetdiagrameditor.cpp
@@ -25,6 +25,7 @@
 #include "ElementsCollection/elementpickerpopup.h"
 #include "shortcutbarsettings.h"
 #include "qetgraphicsitem/conductor.h"
+#include "itemgroups.h"
 #include "commandsearchpopup.h"
 #include "QWidgetAnimation/qwidgetanimation.h"
 #include "autoNum/ui/autonumberingdockwidget.h"
@@ -2078,7 +2079,17 @@ void QETDiagramEditor::selectionGroupTriggered(QAction *action)
         }
 	else if (value == "rotate_selection")
 	{
-		RotateSelectionCommand *c = new RotateSelectionCommand(diagram);
+			//A selection that is exactly one whole group turns as one piece,
+			//as "Pivoter le groupe" does, rather than each member in place
+			//(discussion #1070). Wires follow their symbols either way.
+		QList<QGraphicsItem *> members;
+		for (QGraphicsItem *item : diagram->selectedItems()) {
+			if (item->type() != Conductor::Type) {
+				members << item;
+			}
+		}
+		const bool whole_group = !ItemGroups::soleWholeGroup(members).isNull();
+		RotateSelectionCommand *c = new RotateSelectionCommand(diagram, 90, nullptr, whole_group);
 		if(c->isValid())
 			diagram->undoStack().push(c);
 	}
diff --git a/sources/qetgraphicsitem/element.cpp b/sources/qetgraphicsitem/element.cpp
index fbbc3df5d..eb9dbfbe2 100644
--- a/sources/qetgraphicsitem/element.cpp
+++ b/sources/qetgraphicsitem/element.cpp
@@ -1033,7 +1033,11 @@ QDomElement Element::toXml(
 		QDomElement infos =
 				document.createElement(QStringLiteral("elementInformations"));
 		m_data.m_informations.toXml(infos, QStringLiteral("elementInformation"));
-		element.appendChild(infos);
+			//toXml() skips empty values: an element whose information is
+			//all empty would otherwise be written an empty block, which the
+			//next load reads as no information and the next save drops.
+		if (infos.hasChildNodes())
+			element.appendChild(infos);
 	}
 
 		//Save override properties (For now, only used when the element is a terminal)
diff --git a/sources/qetgraphicsitem/element.h b/sources/qetgraphicsitem/element.h
index 9bb02202d..33d8b752e 100644
--- a/sources/qetgraphicsitem/element.h
+++ b/sources/qetgraphicsitem/element.h
@@ -245,6 +245,7 @@ class Element : public QetGraphicsItem
 		QString linkTypeToString() const;
 
 		void newUuid() {m_uuid = QUuid::createUuid();} 	//create new uuid for this element
+		void setUuid(const QUuid &uuid) {m_uuid = uuid;}
 
 	protected:
 		void drawAxes(QPainter *, const QStyleOptionGraphicsItem *);
diff --git a/sources/qetproject.cpp b/sources/qetproject.cpp
index df45c2c08..b89acc626 100644
--- a/sources/qetproject.cpp
+++ b/sources/qetproject.cpp
@@ -275,6 +275,42 @@ QUuid QETProject::uuid() const
 	return m_uuid;
 }
 
+/**
+	@brief QETProject::derivedItemUuid
+	A uuid for an item of this project that was saved without one, the same
+	on every load of the same file.
+	@p key describes the item by what it is, never by its place in the file
+	or its folio's index: inserting or moving a folio must not change it.
+	Items with the same @p kind and @p key anywhere in the project (a copied
+	folio, two identical symbols stacked on one spot) are told apart by a
+	counter, in load order among those items alone.
+
+	A derived uuid is never one the file already carries: an item saved with
+	a derived uuid and then moved or re-connected keeps it, so a newcomer
+	later taking its old place or ends would otherwise derive the same one.
+	The file's saved uuids are collected before any folio loads
+	(readDiagramsXml()), so the result still depends on the file alone.
+
+	uuids are unique within one project; copies of a project share them, as
+	they share every saved uuid. Anything bringing items in from another
+	project must renew them, as paste does.
+	@return a UUID v5, which cannot collide with the v4 uuids given to new
+	items
+*/
+QUuid QETProject::derivedItemUuid(const QString &kind, const QString &key)
+{
+	static const QUuid derived_ns(QStringLiteral("{7d1e9c3a-5b2f-4e8a-9c61-2f4b8d0e6a17}"));
+	const QString full = kind + QLatin1Char('\n') + key;
+	int &n = m_derived_uuid_keys[full];
+	QUuid uuid;
+	do {
+		uuid = QUuid::createUuidV5(derived_ns,
+								   n ? full + QLatin1Char('\n') + QString::number(n) : full);
+		++n;
+	} while (m_saved_item_uuids.contains(uuid));
+	return uuid;
+}
+
 /**
 	@brief QETProject::init
 */
@@ -1888,6 +1924,18 @@ void QETProject::readDiagramsXml(QDomDocument &xml_project)
 	//Search the diagrams in the project
 	QDomNodeList diagram_nodes = xml_project.elementsByTagName(QStringLiteral("diagram"));
 
+		//Every symbol and wire uuid the file already carries, on any folio,
+		//before a folio derives one for an item saved without: see
+		//derivedItemUuid().
+	for (const QString &tag : {QStringLiteral("element"), QStringLiteral("conductor")}) {
+		const QDomNodeList nodes = xml_project.elementsByTagName(tag);
+		for (int i = 0; i < nodes.size(); ++i) {
+			const QUuid saved(nodes.at(i).toElement().attribute(QStringLiteral("uuid")));
+			if (!saved.isNull())
+				m_saved_item_uuids.insert(saved);
+		}
+	}
+
 	if(dlgWaiting)
 		dlgWaiting->setProgressBarRange(0, diagram_nodes.length()*3);
 
diff --git a/sources/qetproject.h b/sources/qetproject.h
index e05f3b216..35830912c 100644
--- a/sources/qetproject.h
+++ b/sources/qetproject.h
@@ -36,6 +36,7 @@
 #endif
 
 #include <QHash>
+#include <QSet>
 #include <QFuture>
 
 class Diagram;
@@ -107,6 +108,7 @@ class QETProject : public QObject
 		ProjectPropertiesHandler& projectPropertiesHandler();
 		projectDataBase *dataBase();
 		QUuid uuid() const;
+		QUuid derivedItemUuid(const QString &kind, const QString &key);
 		ProjectState state() const;
 		QList<Diagram *> diagrams() const;
 		int folioIndex(const Diagram *) const;
@@ -365,6 +367,8 @@ class QETProject : public QObject
 		QFuture<bool> m_backup_future;
 		KAutoSaveFile m_backup_file;
 		QUuid m_uuid = QUuid::createUuid();
+		QHash<QString, int> m_derived_uuid_keys;
+		QSet<QUuid> m_saved_item_uuids;	//symbol and wire uuids the file carries, see derivedItemUuid()
 		projectDataBase m_data_base;
 		QVector<TerminalStrip *> m_terminal_strip_vector;
 
diff --git a/tests/qttest/CMakeLists.txt b/tests/qttest/CMakeLists.txt
index 9456b5bf4..6bafd77fa 100644
--- a/tests/qttest/CMakeLists.txt
+++ b/tests/qttest/CMakeLists.txt
@@ -344,3 +344,42 @@ if(QET_HAS_SCRIPTING)
   target_compile_definitions(tst_scriptconductoruuid PRIVATE
     "QET_TEST_BINARY_PATH=\"$<TARGET_FILE:qelectrotech>\"")
 endif()
+
+# A symbol saved without a uuid gets the same one on every load, and
+# inserting a folio does not change it. Runs the real binary's --resave on
+# fixtures/qet_bug_repro_resaved.qet with the symbols' uuids stripped.
+add_executable(
+  tst_derivedsymboluuid
+  tst_derivedsymboluuid.cpp)
+add_test(NAME tst_derivedsymboluuid COMMAND tst_derivedsymboluuid)
+add_dependencies(tst_derivedsymboluuid qelectrotech)
+target_link_libraries(tst_derivedsymboluuid PRIVATE Qt::Test Qt::Xml)
+target_compile_definitions(tst_derivedsymboluuid PRIVATE
+  "QET_TEST_BINARY_PATH=\"$<TARGET_FILE:qelectrotech>\"")
+# Saving a project that was just saved changes nothing: runs the real
+# binary's --resave twice on every project in examples/, and on one whose
+# title block holds a single-space value (#973).
+
+add_executable(
+  tst_resaveunchanged
+  tst_resaveunchanged.cpp)
+add_test(NAME tst_resaveunchanged COMMAND tst_resaveunchanged)
+add_dependencies(tst_resaveunchanged qelectrotech)
+target_link_libraries(tst_resaveunchanged PRIVATE Qt::Test)
+target_compile_definitions(tst_resaveunchanged PRIVATE
+  "QET_TEST_BINARY_PATH=\"$<TARGET_FILE:qelectrotech>\""
+  "QET_EXAMPLES_DIR=\"${QET_DIR}/examples\"")
+
+# DiagramContext::fromXml() -- the two readers (QDom for projects, pugixml
+# for element definitions in the collection) give the same values: stray
+# spaces trimmed, accents kept.
+add_executable(
+  tst_diagramcontext
+  tst_diagramcontext.cpp
+  ${QET_DIR}/sources/diagramcontext.cpp
+  ${QET_DIR}/sources/qet.cpp
+  ${QET_DIR}/sources/qeticons.cpp
+  ${QET_DIR}/sources/shortcutmanager.cpp)
+add_test(NAME tst_diagramcontext COMMAND tst_diagramcontext)
+target_include_directories(tst_diagramcontext PRIVATE ${QET_DIR}/sources)
+target_link_libraries(tst_diagramcontext PRIVATE Qt::Test Qt::Widgets Qt::Xml pugixml::pugixml)
diff --git a/tests/qttest/tst_derivedsymboluuid.cpp b/tests/qttest/tst_derivedsymboluuid.cpp
new file mode 100644
index 000000000..e5a0e67f8
--- /dev/null
+++ b/tests/qttest/tst_derivedsymboluuid.cpp
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <QtTest>
+
+#include <QDomDocument>
+#include <QFile>
+#include <QHash>
+#include <QProcess>
+#include <QProcessEnvironment>
+#include <QSet>
+#include <QTemporaryDir>
+#include <QUuid>
+
+// A symbol saved without a uuid must get the same one on every load of the
+// same file, and inserting a folio in front of it must not change it. Until
+// this was fixed it got a random uuid each time (Element::fromXml), which
+// the next save wrote out.
+//
+// Runs the real binary (--resave) on the fixture with its symbols' uuids
+// stripped, and reads the uuids back from the saved file.
+namespace {
+
+QDomDocument load(const QString &path)
+{
+	QDomDocument doc;
+	QFile file(path);
+	if (file.open(QIODevice::ReadOnly))
+		doc.setContent(&file);
+	return doc;
+}
+
+QList<QDomElement> symbols(const QDomElement &diagram)
+{
+	QList<QDomElement> out;
+	const QDomNodeList nodes = diagram.firstChildElement(QStringLiteral("elements"))
+			.elementsByTagName(QStringLiteral("element"));
+	for (int i = 0; i < nodes.size(); ++i) {
+		const QDomElement e = nodes.at(i).toElement();
+		if (e.parentNode().parentNode() == diagram)
+			out << e;
+	}
+	return out;
+}
+
+QList<QDomElement> diagrams(const QDomDocument &doc)
+{
+	QList<QDomElement> out;
+	for (QDomElement d = doc.documentElement().firstChildElement(QStringLiteral("diagram"));
+		 !d.isNull(); d = d.nextSiblingElement(QStringLiteral("diagram")))
+		out << d;
+	return out;
+}
+
+// Symbols without uuids, and no wires (they refer to symbols by uuid).
+void stripUuids(QDomDocument &doc)
+{
+	for (QDomElement d : diagrams(doc)) {
+		for (QDomElement e : symbols(d))
+			e.removeAttribute(QStringLiteral("uuid"));
+		d.removeChild(d.firstChildElement(QStringLiteral("conductors")));
+	}
+}
+
+// type|x|y|orientation -> uuid, for every symbol in the file
+QMultiHash<QString, QString> symbolUuids(const QDomDocument &doc)
+{
+	QMultiHash<QString, QString> out;
+	for (const QDomElement &d : diagrams(doc))
+		for (const QDomElement &e : symbols(d))
+			out.insert(QStringList{e.attribute(QStringLiteral("type")),
+								   e.attribute(QStringLiteral("x")),
+								   e.attribute(QStringLiteral("y")),
+								   e.attribute(QStringLiteral("orientation"))}
+					   .join(QLatin1Char('|')),
+					   e.attribute(QStringLiteral("uuid")));
+	return out;
+}
+
+} // namespace
+
+class tst_derivedsymboluuid : public QObject
+{
+	Q_OBJECT
+
+	QTemporaryDir m_dir;
+	int m_run = 0;
+
+	// Save @p doc, run --resave on it in a sandbox of its own (so a running
+	// QElectroTech cannot answer instead), and return what was saved.
+	QDomDocument resave(const QDomDocument &doc)
+	{
+		const QString in = m_dir.filePath(QStringLiteral("in%1.qet").arg(m_run));
+		const QString out = m_dir.filePath(QStringLiteral("out%1.qet").arg(m_run));
+		const QString home = m_dir.filePath(QStringLiteral("home%1").arg(m_run++));
+		QDir().mkpath(home);
+		QFile f(in);
+		if (!f.open(QIODevice::WriteOnly)) return {};
+		f.write(doc.toByteArray());
+		f.close();
+
+		QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
+		env.insert(QStringLiteral("QT_QPA_PLATFORM"), QStringLiteral("offscreen"));
+		env.insert(QStringLiteral("HOME"), home);
+		env.insert(QStringLiteral("XDG_CONFIG_HOME"), home + QStringLiteral("/config"));
+		env.insert(QStringLiteral("XDG_DATA_HOME"), home + QStringLiteral("/data"));
+		QProcess proc;
+		proc.setProcessEnvironment(env);
+		proc.start(QStringLiteral(QET_TEST_BINARY_PATH),
+				   {QStringLiteral("--resave"), in, out});
+		if (!proc.waitForFinished(60000) || proc.exitCode() != 0) return {};
+		return load(out);
+	}
+
+	QDomDocument fixture()
+	{
+		QDomDocument doc = load(QFINDTESTDATA("fixtures/qet_bug_repro_resaved.qet"));
+		stripUuids(doc);
+		return doc;
+	}
+
+private slots:
+	void initTestCase()
+	{
+		QVERIFY(m_dir.isValid());
+		QVERIFY(QFile::exists(QStringLiteral(QET_TEST_BINARY_PATH)));
+		QVERIFY(!fixture().isNull());
+	}
+
+	void sameUuidsOnEveryLoad()
+	{
+		const QMultiHash<QString, QString> a = symbolUuids(resave(fixture()));
+		const QMultiHash<QString, QString> b = symbolUuids(resave(fixture()));
+		QCOMPARE(a.size(), 9);      // the fixture's placed symbols
+		QCOMPARE(a, b);
+		for (const QString &u : a)
+			QVERIFY2(!QUuid(u).isNull(), qPrintable(u));
+		QCOMPARE(QSet<QString>(a.begin(), a.end()).size(), a.size());
+	}
+
+	void insertingAFolioChangesNothing()
+	{
+		QDomDocument moved = fixture();
+		QDomElement first = diagrams(moved).first();
+		QDomElement blank = first.cloneNode(false).toElement();
+		blank.setAttribute(QStringLiteral("title"), QStringLiteral("new"));
+		blank.appendChild(moved.createElement(QStringLiteral("elements")));
+		moved.documentElement().insertBefore(blank, first);
+
+		const QMultiHash<QString, QString> after = symbolUuids(resave(moved));
+		QCOMPARE(after.size(), 9);
+		QCOMPARE(after, symbolUuids(resave(fixture())));
+	}
+
+	void savedUuidsAreKept()
+	{
+		QDomDocument doc = load(QFINDTESTDATA("fixtures/qet_bug_repro_resaved.qet"));
+		QCOMPARE(symbolUuids(resave(doc)), symbolUuids(doc));
+	}
+
+	// A symbol keeps its derived uuid once saved, even when moved. A symbol
+	// saved without a uuid that later turns up on the spot it left (a hand
+	// edit, an older version, another tool) would derive the same uuid: it
+	// must get another one instead.
+	void newcomerOnAMovedSymbolsSpotGetsAnotherUuid()
+	{
+		QDomDocument doc = resave(fixture());
+		QDomElement moved = symbols(diagrams(doc).first()).first();
+		QVERIFY(!QUuid(moved.attribute(QStringLiteral("uuid"))).isNull());
+		QDomElement newcomer = moved.cloneNode(true).toElement();
+		newcomer.removeAttribute(QStringLiteral("uuid"));
+		const QDomNodeList terminals = newcomer.elementsByTagName(QStringLiteral("terminal"));
+		for (int i = 0; i < terminals.size(); ++i)
+			terminals.at(i).toElement().setAttribute(QStringLiteral("id"), 90000 + i);
+		moved.setAttribute(QStringLiteral("x"), moved.attribute(QStringLiteral("x")).toInt() + 500);
+		moved.parentNode().appendChild(newcomer);
+
+		const QMultiHash<QString, QString> after = symbolUuids(resave(doc));
+		QCOMPARE(after.size(), 10);
+		QCOMPARE(QSet<QString>(after.begin(), after.end()).size(), 10);
+	}
+
+	void stackedIdenticalSymbolsDiffer()
+	{
+		QDomDocument doc = fixture();
+		QDomElement one = symbols(diagrams(doc).first()).first();
+		QDomElement copy = one.cloneNode(true).toElement();
+			//A copy's terminals carry their own file ids; a symbol whose
+			//terminal ids are already taken is not loaded at all.
+		const QDomNodeList terminals = copy.elementsByTagName(QStringLiteral("terminal"));
+		for (int i = 0; i < terminals.size(); ++i)
+			terminals.at(i).toElement().setAttribute(QStringLiteral("id"), 90000 + i);
+		one.parentNode().appendChild(copy);
+
+		const QStringList both = symbolUuids(resave(doc)).values(
+					QStringList{one.attribute(QStringLiteral("type")),
+								one.attribute(QStringLiteral("x")),
+								one.attribute(QStringLiteral("y")),
+								one.attribute(QStringLiteral("orientation"))}
+					.join(QLatin1Char('|')));
+		QCOMPARE(both.size(), 2);
+		QVERIFY(both.at(0) != both.at(1));
+	}
+};
+
+QTEST_APPLESS_MAIN(tst_derivedsymboluuid)
+
+#include "tst_derivedsymboluuid.moc"
diff --git a/tests/qttest/tst_diagramcontext.cpp b/tests/qttest/tst_diagramcontext.cpp
new file mode 100644
index 000000000..f0e004b0d
--- /dev/null
+++ b/tests/qttest/tst_diagramcontext.cpp
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <QtTest>
+
+#include "diagramcontext.h"
+#include "qetapp.h"
+
+QString QETApp::m_interface_language;
+
+/**
+	DiagramContext::fromXml() has two readers: QDom, for projects, and
+	pugixml, for element definitions in the collection. Both must give the
+	values the next save writes -- stray spaces around real content trimmed,
+	accented characters kept.
+*/
+class tst_diagramcontext : public QObject
+{
+	Q_OBJECT
+
+	static QByteArray xml(const QString &value)
+	{
+		return QStringLiteral(
+				   "<elementInformations>"
+				   "<elementInformation name=\"v\" show=\"1\">%1</elementInformation>"
+				   "</elementInformations>")
+				.arg(value)
+				.toUtf8();
+	}
+
+	static QString fromDom(const QByteArray &data)
+	{
+		QDomDocument doc;
+		if (!doc.setContent(data)) return QStringLiteral("<parse error>");
+		DiagramContext dc;
+		dc.fromXml(doc.documentElement(), QStringLiteral("elementInformation"));
+		return dc.value(QStringLiteral("v")).toString();
+	}
+
+	static QString fromPugi(const QByteArray &data)
+	{
+		pugi::xml_document doc;
+		if (!doc.load_buffer(data.constData(), size_t(data.size())))
+			return QStringLiteral("<parse error>");
+		DiagramContext dc;
+		dc.fromXml(doc.document_element(), QStringLiteral("elementInformation"));
+		return dc.value(QStringLiteral("v")).toString();
+	}
+
+private slots:
+	void bothReadersAgree_data()
+	{
+		QTest::addColumn<QString>("value");
+		QTest::addColumn<QString>("expected");
+
+		QTest::newRow("plain")       << "PRISE" << "PRISE";
+		QTest::newRow("stray spaces") << " PRISE  " << "PRISE";
+		QTest::newRow("accents")     << "Armoire façade été" << "Armoire façade été";
+		QTest::newRow("accents and stray spaces") << "  Moteur à cage " << "Moteur à cage";
+		QTest::newRow("non-Latin")   << "Двигатель 電機" << "Двигатель 電機";
+	}
+
+	void bothReadersAgree()
+	{
+		QFETCH(QString, value);
+		QFETCH(QString, expected);
+		QCOMPARE(fromDom(xml(value)), expected);
+		QCOMPARE(fromPugi(xml(value)), expected);
+	}
+};
+
+QTEST_APPLESS_MAIN(tst_diagramcontext)
+
+#include "tst_diagramcontext.moc"
diff --git a/tests/qttest/tst_itemgroups.cpp b/tests/qttest/tst_itemgroups.cpp
index 079c8c94c..217ea7d41 100644
--- a/tests/qttest/tst_itemgroups.cpp
+++ b/tests/qttest/tst_itemgroups.cpp
@@ -121,6 +121,48 @@ private slots:
 		b = nullptr;
 	}
 
+	// A second click on a member of a group selected whole picks that member
+	// out; a click on a member of a group not selected whole does not.
+	void aMemberOfAWholeGroupCanBePicked()
+	{
+		select({a, b});
+		QCOMPARE(ItemGroups::memberToPick(a), a);
+		QCOMPARE(ItemGroups::memberToPick(b), b);
+	}
+
+	void aMemberOfAPartlySelectedGroupIsNotPicked()
+	{
+		select({a});       // after one member was picked
+		QCOMPARE(ItemGroups::memberToPick(a), nullptr);
+		select({});
+		QCOMPARE(ItemGroups::memberToPick(a), nullptr);
+	}
+
+	void anUngroupedItemIsNotPicked()
+	{
+		select({c});
+		QCOMPARE(ItemGroups::memberToPick(c), nullptr);
+		QCOMPARE(ItemGroups::memberToPick(nullptr), nullptr);
+	}
+
+	void aGroupOfOneIsNotPicked()
+	{
+		ItemGroups::setGroup(e, QUuid());   // g2 is now d alone
+		select({d});
+		QCOMPARE(ItemGroups::memberToPick(d), nullptr);
+	}
+
+	// A click lands on a symbol's own text, not on the symbol: the member is
+	// the nearest grouped ancestor.
+	void aClickOnAMembersChildPicksTheMember()
+	{
+		auto child = new QGraphicsRectItem(0, 0, 2, 2, a);
+		QCOMPARE(ItemGroups::groupedItem(child), a);
+		select({a, b});
+		QCOMPARE(ItemGroups::memberToPick(child), a);
+		QCOMPARE(ItemGroups::groupedItem(c), nullptr);
+	}
+
 	void xmlRoundTrip()
 	{
 		QDomDocument doc;
@@ -136,6 +178,34 @@ private slots:
 		ItemGroups::setGroup(a, QUuid());
 		QVERIFY(ItemGroups::groupOf(a).isNull());
 	}
+
+	// Rotate turns a selection that is exactly one whole group as one piece.
+	void aWholeGroupAloneIsASoleWholeGroup()
+	{
+		select({a, b});
+		QCOMPARE(ItemGroups::soleWholeGroup(selection()), g1);
+	}
+
+	void aPickedMemberIsNotAWholeGroup()
+	{
+		select({a});
+		QVERIFY(ItemGroups::soleWholeGroup(selection()).isNull());
+	}
+
+	void aGroupWithOtherItemsIsNotASoleGroup()
+	{
+		select({a, b, c});
+		QVERIFY(ItemGroups::soleWholeGroup(selection()).isNull());
+		select({a, b, d, e});
+		QVERIFY(ItemGroups::soleWholeGroup(selection()).isNull());
+	}
+
+	void ungroupedItemsAreNotAGroup()
+	{
+		select({c});
+		QVERIFY(ItemGroups::soleWholeGroup(selection()).isNull());
+		QVERIFY(ItemGroups::soleWholeGroup({}).isNull());
+	}
 };
 
 QTEST_MAIN(tst_itemgroups)
diff --git a/tests/qttest/tst_resaveunchanged.cpp b/tests/qttest/tst_resaveunchanged.cpp
new file mode 100644
index 000000000..55fed0942
--- /dev/null
+++ b/tests/qttest/tst_resaveunchanged.cpp
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <QtTest>
+
+#include <QDir>
+#include <QFile>
+#include <QProcess>
+#include <QProcessEnvironment>
+#include <QRegularExpression>
+#include <QTemporaryDir>
+
+// Saving a project that was just saved must change nothing. Two things
+// made the second save differ from the first, both cleanup done on save
+// but not on load:
+//  - symbol information whose values were all empty was written as an
+//    empty <elementInformations/> block, which the next load read as no
+//    information and the next save dropped (Projet_vierge.qet);
+//  - information values were trimmed on save but not on load, so a label
+//    with stray spaces kept them in its displayed copy until the project
+//    was opened again (m_000.qet).
+// Runs the real binary's --resave twice on every example, and on a
+// project whose title block holds a value that is a single space (#973).
+class tst_resaveunchanged : public QObject
+{
+	Q_OBJECT
+
+	QTemporaryDir m_dir;
+	int m_run = 0;
+
+	// --resave @p in to a new file, in a sandbox of its own (so a running
+	// QElectroTech cannot answer instead); returns the new file's path.
+	QString resave(const QString &in)
+	{
+		const QString out = m_dir.filePath(QStringLiteral("out%1.qet").arg(m_run));
+		const QString home = m_dir.filePath(QStringLiteral("home%1").arg(m_run++));
+		QDir().mkpath(home);
+		QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
+		env.insert(QStringLiteral("QT_QPA_PLATFORM"), QStringLiteral("offscreen"));
+		env.insert(QStringLiteral("HOME"), home);
+		env.insert(QStringLiteral("XDG_CONFIG_HOME"), home + QStringLiteral("/config"));
+		env.insert(QStringLiteral("XDG_DATA_HOME"), home + QStringLiteral("/data"));
+		QProcess proc;
+		proc.setProcessEnvironment(env);
+		proc.start(QStringLiteral(QET_TEST_BINARY_PATH), {QStringLiteral("--resave"), in, out});
+		if (!proc.waitForFinished(120000) || proc.exitCode() != 0) return {};
+		return out;
+	}
+
+	static QByteArray read(const QString &path)
+	{
+		QFile f(path);
+		return f.open(QIODevice::ReadOnly) ? f.readAll() : QByteArray();
+	}
+
+private slots:
+	void initTestCase()
+	{
+		QVERIFY(m_dir.isValid());
+		QVERIFY(QFile::exists(QStringLiteral(QET_TEST_BINARY_PATH)));
+	}
+
+	// Projet_vierge.qet has empty information values, m_000.qet values
+	// with stray spaces; every other example is here so a new cause shows.
+	void secondSaveChangesNothing_data()
+	{
+		QTest::addColumn<QString>("project");
+		const QDir examples(QStringLiteral(QET_EXAMPLES_DIR));
+		const QStringList projects =
+				examples.entryList({QStringLiteral("*.qet")}, QDir::Files, QDir::Name);
+		QVERIFY(!projects.isEmpty());
+		for (const QString &project : projects)
+			QTest::newRow(project.toUtf8().constData()) << examples.filePath(project);
+	}
+
+	void secondSaveChangesNothing()
+	{
+		QFETCH(QString, project);
+		const QString first = resave(project);
+		QVERIFY2(!first.isEmpty(), "first --resave failed");
+		const QString second = resave(first);
+		QVERIFY2(!second.isEmpty(), "second --resave failed");
+		const QByteArray a = read(first), b = read(second);
+		QVERIFY(!a.isEmpty());
+		QVERIFY2(a == b, "the second save changed the file");
+	}
+
+	// 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()
+	{
+		QByteArray xml = read(QStringLiteral(QET_EXAMPLES_DIR "/Projet_vierge.qet"));
+		QVERIFY(xml.contains("<properties>"));
+		xml.replace("<properties>",
+					"<properties>"
+					"<property show=\"1\" name=\"space\"> </property>"
+					"<property show=\"1\" name=\"accents\">Armoire façade été</property>");
+		const QString in = m_dir.filePath(QStringLiteral("space.qet"));
+		QFile f(in);
+		QVERIFY(f.open(QIODevice::WriteOnly));
+		f.write(xml);
+		f.close();
+
+		const QString first = resave(in);
+		QVERIFY2(!first.isEmpty(), "first --resave failed");
+		const QString second = resave(first);
+		QVERIFY2(!second.isEmpty(), "second --resave failed");
+		const QByteArray a = read(first), b = read(second);
+		QVERIFY2(a == b, "the second save changed the file");
+
+		const QString saved = QString::fromUtf8(b);
+		QVERIFY2(saved.contains(QRegularExpression(
+					 QStringLiteral("<property [^>]*name=\"space\"[^>]*> </property>"))),
+				 "the single-space value was lost");
+		QVERIFY2(saved.contains(QRegularExpression(
+					 QStringLiteral("<property [^>]*name=\"accents\"[^>]*>Armoire façade été</property>"))),
+				 "the accented value changed");
+	}
+};
+
+QTEST_APPLESS_MAIN(tst_resaveunchanged)
+
+#include "tst_resaveunchanged.moc"