psxbios: Better realloc implementation

This should be closer to the real behaviour as described by nocash.
It doesn't do any bcopy though but it shouldn't be too much different
other than that.

1 files changed, 18 insertions, 3 deletions

diff --git a/libpcsxcore/psxbios.c b/libpcsxcore/psxbios.c
index 90c11ae..fc28ff8 100644
--- a/libpcsxcore/psxbios.c
+++ b/libpcsxcore/psxbios.c
@@ -1010,9 +1010,24 @@ void psxBios_realloc() { // 0x38
 #endif
 
 	a0 = block;
-	psxBios_free();
-	a0 = size;
-	psxBios_malloc();
+	/* If "old_buf" is zero, executes malloc(new_size), and returns r2=new_buf (or 0=failed). */
+	if (block == 0)
+	{
+		psxBios_malloc();
+	}
+	/* Else, if "new_size" is zero, executes free(old_buf), and returns r2=garbage. */
+	else if (size == 0)
+	{
+		psxBios_free();
+	}
+	/* Else, executes malloc(new_size), bcopy(old_buf,new_buf,new_size), and free(old_buf), and returns r2=new_buf (or 0=failed). */
+	/* Note that it is not quite implemented this way here. */
+	else
+	{
+		psxBios_free();
+		a0 = size;
+		psxBios_malloc();
+	}
 }