=str Skip parsing when buffer size <= 0.

stream-tests/src/test/scala/org/apache/pekko/stream/scaladsl/JsonFramingSpec.scala

@@ -545,6 +545,22 @@ class JsonFramingSpec extends PekkoSpec {
       probe.request(1).expectError() shouldBe a[PartialObjectException]
     }
 
+    "complete when completing inside an empty chars" in {
+      val input = ByteString("   ")
+      val probe = Source.single(input).via(JsonFraming.objectScanner(48)).runWith(TestSink.probe)
+
+      probe.ensureSubscription()
+      probe.request(1).expectComplete()
+    }
+
+    "complete when completing with an empty byte string" in {
+      val input = ByteString()
+      val probe = Source.single(input).via(JsonFraming.objectScanner(48)).runWith(TestSink.probe)
+
+      probe.ensureSubscription()
+      probe.request(1).expectComplete()
+    }
+
     "fail when pushing and inside an object" in {
       val input = """  { "name": "john" }, {  """
       Source

stream/src/main/scala/org/apache/pekko/stream/impl/JsonObjectParser.scala

@@ -115,20 +115,21 @@ import pekko.util.ByteString
   private def seekObject(): Boolean = {
     completedObject = false
     val bufSize = buffer.length
+    if (bufSize > 0) {
+      skipToNextObject(bufSize)
+      val maxObjectLengthIndex = if (pos + maximumObjectLength < 0) Int.MaxValue else pos + maximumObjectLength
 
-    skipToNextObject(bufSize)
-    val maxObjectLengthIndex = if (pos + maximumObjectLength < 0) Int.MaxValue else pos + maximumObjectLength
+      while (pos < bufSize && pos < maxObjectLengthIndex && !completedObject) {
+        val input = buffer(pos)
+        proceed(input)
+        pos += 1
+      }
 
-    while (pos < bufSize && pos < maxObjectLengthIndex && !completedObject) {
-      val input = buffer(pos)
-      proceed(input)
-      pos += 1
-    }
+      if (pos >= maxObjectLengthIndex)
+        throw new FramingException(s"""JSON element exceeded maximumObjectLength ($maximumObjectLength bytes)!""")
 
-    if (pos >= maxObjectLengthIndex)
-      throw new FramingException(s"""JSON element exceeded maximumObjectLength ($maximumObjectLength bytes)!""")
-
-    completedObject
+      completedObject
+    } else false
   }
 
   private def skipToNextObject(bufSize: Int): Unit =