SCI: Make kMemory behavior like original SCI

We added 1 to the size as a workaround, but it's not really a
workaround, because original SCI allocated at least 2 bytes more.
They also made sure the size is even. We now do the same.

1 files changed, 13 insertions, 6 deletions

diff --git a/engines/sci/engine/kmisc.cpp b/engines/sci/engine/kmisc.cpp
index 9d47a37bca..f4bb4ff85b 100644
--- a/engines/sci/engine/kmisc.cpp
+++ b/engines/sci/engine/kmisc.cpp
@@ -268,7 +268,10 @@ reg_t kMemory(EngineState *s, int argc, reg_t *argv) {
 	switch (argv[0].toUint16()) {
 	case K_MEMORY_ALLOCATE_CRITICAL: {
 		int byteCount = argv[1].toUint16();
-		// WORKAROUND:
+		// Sierra themselves allocated at least 2 bytes more than requested.
+		// Probably as a safety margin. And they also made size even.
+		//
+		// This behavior is required by at least these:
 		//  - pq3 (multilingual) room 202
 		//     when plotting crimes, allocates the returned bytes from kStrLen
 		//     on "W" and "E" and wants to put a string in there, which doesn't
@@ -276,18 +279,22 @@ reg_t kMemory(EngineState *s, int argc, reg_t *argv) {
 		//  - lsl5 (multilingual) room 280
 		//     allocates memory according to a previous kStrLen for the name of
 		//     the airport ladies (bug #3093818), which isn't enough
-
-		// We always allocate 1 byte more, because of this
-		byteCount++;
+		byteCount += 2 + (byteCount & 1);
 
 		if (!s->_segMan->allocDynmem(byteCount, "kMemory() critical", &s->r_acc)) {
 			error("Critical heap allocation failed");
 		}
 		break;
 	}
-	case K_MEMORY_ALLOCATE_NONCRITICAL:
-		s->_segMan->allocDynmem(argv[1].toUint16(), "kMemory() non-critical", &s->r_acc);
+	case K_MEMORY_ALLOCATE_NONCRITICAL: {
+		int byteCount = argv[1].toUint16();
+
+		// See above
+		byteCount += 2 + (byteCount & 1);
+
+		s->_segMan->allocDynmem(byteCount, "kMemory() non-critical", &s->r_acc);
 		break;
+	}
 	case K_MEMORY_FREE :
 		if (!s->_segMan->freeDynmem(argv[1])) {
 			if (g_sci->getGameId() == GID_QFG1VGA) {