Improve errors for copying.

ChangeLog

@@ -1,19 +1,24 @@
-2024-23-09: Hugo Melder <[email protected]>
+2024-10-13 Richard Frith-Macdonald <[email protected]>
+
+	* Source/NSFileManager.m: Create an NSError object when we fail to
+	copy because the destination item already exists.
+
+2024-09-23: Hugo Melder <[email protected]>
 
 	* Headers/Foundation/NSThread.h:
 	* Source/NSString.m:
 	* Source/NSThread.m:
 	Cache ICU collator in thread-local storage to avoid
 	expensive construction when comparing strings.
 
-2024-13-08: Hugo Melder <[email protected]>
+2024-08-13: Hugo Melder <[email protected]>
 
 	* Source/NSOperation.m:
 	* Headers/Foundation/NSOperation.h:
 	Give NSOperationQueue worker threads a proper thread
 	name for easy identification.
 
-2024-12-08 Hugo Melder <[email protected]>
+2024-08-12 Hugo Melder <[email protected]>
 	* Source/NSThread.m:
 	Fix threadPriority and setThreadPriority: on Android.
 

Source/NSFileManager.m

@@ -1338,11 +1338,13 @@ - (BOOL) copyPath: (NSString*)source
 
   if ([self fileExistsAtPath: destination] == YES)
     {
+      [self _setLastError: @"Could not copy - destination already exists"];
       return NO;
     }
   attrs = [self fileAttributesAtPath: source traverseLink: NO];
   if (attrs == nil)
     {
+      [self _setLastError: @"Cound not copy - destination is not readable"];
       return NO;
     }
   fileType = [attrs fileType];
@@ -1368,7 +1370,8 @@ - (BOOL) copyPath: (NSString*)source
       if ([[destination stringByAppendingString: @"/"]
 	hasPrefix: [source stringByAppendingString: @"/"]])
 	{
-	  [self _setLastError: @"Could not copy - destination is a descendant of source"];
+	  [self _setLastError:
+	    @"Could not copy - destination is a descendant of source"];
 	  return NO;
 	}