Ensure that cam.capture() can be called more than once for an instance.

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>

lib/camera.js

@@ -123,8 +123,10 @@ class Camera extends Stream {
         ]);
       },
       stop() {
-        state.process.kill('SIGTERM');
-        state.process = null;
+        if (state.process) {
+          state.process.kill('SIGTERM');
+          state.process = null;
+        }
       }
     };
 
@@ -170,20 +172,22 @@ class Camera extends Stream {
         state.stream = null;
         this.stream();
       });
-    }
-
-    let incoming = state.stream.pipe(new MjpegConsumer());
-
-    incoming.on('data', frame => state.frame = frame);
-    incoming.on('error', () => this.stream());
-    incoming.pipe(this);
+      let incoming = state.stream.pipe(new MjpegConsumer());
 
+      incoming.on('data', frame => state.frame = frame);
+      incoming.on('error', () => {
+        state.stream = null;
+        this.stream();
+      });
+      incoming.pipe(this);
+    }
     return this;
   }
 
   capture() {
     let cs = new CaptureStream(this);
 
+    this.stream();
     this.once('data', data => {
       cs.push(data);
       cs.push(null);

test/unit/camera.js

@@ -68,7 +68,7 @@ exports['av.Camera'] = {
     });
 
     cam.on('stop', () => {
-      test.equal(this.write.lastCall.args[0], buffer);
+      test.ok(this.write.lastCall.args[0].equals(buffer));
       test.equal(this.write.callCount, 1);
       // This is null because we bypassed the frame setting
       // mechanism below when `cam.emit('data', buffer);`
@@ -80,6 +80,37 @@ exports['av.Camera'] = {
     cam.emit('data', buffer);
   },
 
+  captureMultiple(test) {
+    test.expect(8);
+
+    var buffer = new Buffer([0]);
+    var cam = new av.Camera();
+    var writable = new Writable();
+
+    this.sandbox.spy(cam, 'capture');
+    this.sandbox.spy(cam, 'stream');
+
+    cam.on('stop', () => {
+      test.ok(buffer.equals(buffer));
+      buffer.writeInt8(cam.capture.callCount, 0);
+
+      if (cam.capture.callCount === 4) {
+        test.equal(cam.stream.callCount, 4);
+        test.done();
+      } else {
+        let cs = cam.capture();
+        cam.emit('data', buffer);
+
+        test.equal(cs.read(1).readUInt8(0), cam.capture.callCount - 1);
+
+        cs.pipe(writable);
+      }
+    });
+
+    cam.capture().pipe(writable);
+    cam.emit('data', buffer);
+  },
+
   spawned(test) {
     test.expect(3);