if the backend sets a different sample rate, check if it is supported:

WildMidi_Init() accepts uint16_t as rate, therefore, reject any values
greater than 65535.

src/player/out_alsa.c

@@ -80,6 +80,10 @@ static int open_alsa_output(const char *pcmname, unsigned int *rate) {
         goto fail;
     }
     if (r != *rate) {
+        if (*rate > 65535) { /* WildMidi_Init() accepts uint16_t as rate */
+            fprintf(stderr, "ALSA: an unsupported sample rate (%uHz) was set\r\n", *rate);
+            goto fail;
+        }
         fprintf(stderr, "ALSA: sample rate set to %uHz instead of %u\r\n", *rate, r);
     }
 

src/player/out_netbsd.c

@@ -86,14 +86,21 @@ static int open_netbsd_output(const char *pcmname, unsigned int *rate)
     ainfo.blocksize = 0;
 
     if (ioctl(audio_fd, AUDIO_SETINFO, &ainfo) < 0) {
-        fprintf(stderr, "netbsdaudio: AUDIO_SETINFO failed!\n");
+        fprintf(stderr, "netbsdaudio: AUDIO_SETINFO failed!\r\n");
         goto err1;
     }
     if (ioctl(audio_fd, AUDIO_GETINFO, &ainfo) < 0) {
         err0:
-        fprintf(stderr, "netbsdaudio: AUDIO_GETINFO failed!\n");
+        fprintf(stderr, "netbsdaudio: AUDIO_GETINFO failed!\r\n");
         goto err1;
     }
+    if (ainfo.play.sample_rate != *rate) {
+        if (ainfo.play.sample_rate > 65535) { /* WildMidi_Init() accepts uint16_t as rate */
+            fprintf(stderr, "netbsdaudio: an unsupported sample rate (%uHz) was set\r\n", ainfo.play.sample_rate);
+            goto fail;
+        }
+        fprintf(stderr, "netbsdaudio: sample rate set to %uHz instead of %u\r\n", ainfo.play.sample_rate, *rate);
+    }
     *rate = ainfo.play.sample_rate;
 
     return 0;

src/player/out_oss.c

@@ -90,6 +90,10 @@ static int open_oss_output(const char *pcmname, unsigned int *rate) {
         goto fail;
     }
     if (r != *rate) {
+        if (*rate > 65535) { /* WildMidi_Init() accepts uint16_t as rate */
+            fprintf(stderr, "OSS: set an unsupported sample rate (%uHz) was set\r\n", *rate);
+            goto fail;
+        }
         fprintf(stderr, "OSS: sample rate set to %uHz instead of %u\r\n", *rate, r);
     }
 

src/player/out_sndio.c

@@ -86,6 +86,13 @@ static int open_sndio_output(const char *output, unsigned int *rate)
         goto error;
     }
 
+    if (par.rate != *rate) {
+        if (par.rate > 65535) { /* WildMidi_Init() accepts uint16_t as rate */
+            fprintf(stderr, "sndio: an unsupported sample rate (%uHz) was set\r\n", par.rate);
+            goto fail;
+        }
+        fprintf(stderr, "sndio: sample rate set to %uHz instead of %u\r\n", par.rate, *rate);
+    }
     *rate = par.rate; /* update rate with the received value */
     return 0;