NSMatrix: no cell class when a prototype is used

-cellClass returned the prototype cell's class when the matrix was set
up with a prototype.  OS X returns nil in that case (the cell class and
the prototype are alternatives).  Return Nil while a prototype is set.
The stored class is left untouched, so the coder and cell creation are
unaffected.

Author: DTW-Thalion

ChangeLog

@@ -1,3 +1,12 @@
+2026-07-12 Todd White <todd.white@thalion.global>
+
+	* Source/NSMatrix.m (-[NSMatrix cellClass]): Return Nil when the matrix
+	uses a cell prototype, as OS X does, rather than the prototype cell's
+	class.
+	* Tests/gui/NSMatrix/cellClassPrototype.m:
+	* Tests/gui/NSMatrix/TestInfo:
+	New test for the cell class / prototype relationship.
+
 2026-07-12 Todd White <todd.white@thalion.global>
 
 	* Tests/gui/NSTableHeaderCell/headerCell.m:

Source/NSMatrix.m

@@ -3009,6 +3009,11 @@ - (void) setCellClass: (Class)classId
  */
 - (Class) cellClass
 {
+  /* A matrix that uses a cell prototype has no cell class, as on OS X.  */
+  if (_cellPrototype != nil)
+    {
+      return Nil;
+    }
   return _cellClass;
 }
 

Tests/gui/NSMatrix/TestInfo

@@ -0,0 +1,66 @@
+/* A matrix that uses a cell prototype has no cell class, as on OS X:
+   -cellClass returns Nil while a prototype is set, and returns the class
+   again once a cell class is set (which clears the prototype). */
+#include "Testing.h"
+
+#include <Foundation/NSAutoreleasePool.h>
+#include <Foundation/NSGeometry.h>
+
+#include <AppKit/NSApplication.h>
+#include <AppKit/NSButtonCell.h>
+#include <AppKit/NSMatrix.h>
+
+int
+main(int argc, char **argv)
+{
+  CREATE_AUTORELEASE_POOL(arp);
+
+  START_SET("NSMatrix cell class vs prototype")
+
+  NS_DURING
+  {
+    [NSApplication sharedApplication];
+  }
+  NS_HANDLER
+  {
+    if ([[localException name] isEqualToString: NSInternalInconsistencyException])
+      SKIP("It looks like GNUstep backend is not yet installed")
+  }
+  NS_ENDHANDLER
+
+  /* Built with a prototype: no cell class. */
+  {
+    NSButtonCell *proto = AUTORELEASE([[NSButtonCell alloc] init]);
+    NSMatrix *m = AUTORELEASE([[NSMatrix alloc] initWithFrame: NSMakeRect(0, 0, 100, 100)
+                                             mode: NSListModeMatrix
+                                        prototype: proto
+                                     numberOfRows: 1
+                                  numberOfColumns: 1]);
+
+    pass([m prototype] != nil, "the prototype is set");
+    pass([m cellClass] == Nil, "a matrix with a prototype has no cell class");
+  }
+
+  /* Setting a cell class clears the prototype and reports the class. */
+  {
+    NSMatrix *m = AUTORELEASE([[NSMatrix alloc] initWithFrame: NSMakeRect(0, 0, 100, 100)]);
+
+    [m setCellClass: [NSButtonCell class]];
+    pass([m cellClass] == [NSButtonCell class], "setCellClass: reports the cell class");
+    pass([m prototype] == nil, "setCellClass: clears the prototype");
+  }
+
+  /* Setting a prototype on that matrix hides the cell class again. */
+  {
+    NSMatrix *m = AUTORELEASE([[NSMatrix alloc] initWithFrame: NSMakeRect(0, 0, 100, 100)]);
+
+    [m setCellClass: [NSButtonCell class]];
+    [m setPrototype: AUTORELEASE([[NSButtonCell alloc] init])];
+    pass([m cellClass] == Nil, "setPrototype: makes the cell class Nil again");
+  }
+
+  END_SET("NSMatrix cell class vs prototype")
+
+  DESTROY(arp);
+  return 0;
+}