Undo: only show warning message if dives were actually edited

The multiple-dives-edited message was shown even if the value was
not changed. Notably, when tab-flipping through the dive fields.

Therefore, changed the execute_edit() function to return zero
when no command was executed. For this, return a boolean from
the execute() function indicating whether the command was really
executed or trashed.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

3 files changed, 10 insertions, 8 deletions

diff --git a/desktop-widgets/command.cpp b/desktop-widgets/command.cpp
index 35010b3c3..78f849651 100644
--- a/desktop-widgets/command.cpp
+++ b/desktop-widgets/command.cpp
@@ -148,9 +148,8 @@ void purgeUnusedDiveSites()
 // Execute an edit-command and return number of edited dives
 static int execute_edit(EditDivesBase *cmd)
 {
-	int res = cmd->numDives();
-	execute(cmd);
-	return res;
+	int count = cmd->numDives();
+	return execute(cmd) ? count : 0;
 }
 
 // Dive editing related commands
diff --git a/desktop-widgets/command_base.cpp b/desktop-widgets/command_base.cpp
index 26a587f7c..9316135dd 100644
--- a/desktop-widgets/command_base.cpp
+++ b/desktop-widgets/command_base.cpp
@@ -38,12 +38,15 @@ QAction *redoAction(QObject *parent)
 	return undoStack.createRedoAction(parent, QCoreApplication::translate("Command", "&Redo"));
 }
 
-void execute(Base *cmd)
+bool execute(Base *cmd)
 {
-	if (cmd->workToBeDone())
+	if (cmd->workToBeDone()) {
 		undoStack.push(cmd);
-	else
+		return true;
+	} else {
 		delete cmd;
+		return false;
+	}
 }
 
 } // namespace Command
diff --git a/desktop-widgets/command_base.h b/desktop-widgets/command_base.h
index cf8f248d2..85ca6f8de 100644
--- a/desktop-widgets/command_base.h
+++ b/desktop-widgets/command_base.h
@@ -168,8 +168,8 @@ public:
 
 // Put a command on the undoStack (and take ownership), but test whether there
 // is something to be done beforehand by calling the workToBeDone() function.
-// If nothing is to be done, the command will be deleted.
-void execute(Base *cmd);
+// If nothing is to be done, the command will be deleted and false is returned.
+bool execute(Base *cmd);
 
 } // namespace Command