Check for svpos or shpos == 0.

diff --git a/custom.cpp b/custom.cpp
index ac776ebc45a55f88c28d504c9503a7ccd3fc00a3..ffac056aa13089e84a4aa8def649164bcb7b7149 100644 (file)
--- a/custom.cpp
+++ b/custom.cpp
@@ -1383,7 +1383,10 @@ void compute_vsynctime(void)
                vsynctimebase = (frame_time_t)(syncbase / fake_vblank_hz);
        }
        vsynctimebase_orig = vsynctimebase;
-       cputimebase = syncbase / ((uae_u32)(svpos * shpos));
+       cputimebase = 0;
+       if (svpos > 0 && shpos > 0) {
+               cputimebase = syncbase / ((uae_u32)(svpos * shpos));
+       }
        if (cputimebase == 0) {
                cputimebase = 1;
        }