fix test 'validation of field value sizes'

src/test/scala/org/ergoplatform/nodeView/state/ErgoStateContextSpec.scala

@@ -58,27 +58,26 @@ class ErgoStateContextSpec extends HistoryTestHelpers {
       fb.copy(extension = newExtension)
     }
 
-    // stress-test to trigger sporadic failure https://github.com/ergoplatform/ergo/issues/2114
-    for (i <- 1 to 10000) {
-    i == i // leave this, otherwise strange failures
+    // regression stress-test for sporadic failure https://github.com/ergoplatform/ergo/issues/2114
+    for (i <- 1 to 1000) {
 
     // checks, specific for extension
     // validation of field keys size
     val imvKey = extensionKvGen(Extension.FieldKeySize - 1, Extension.FieldValueMaxSize).sample.get
     sc.appendFullBlock(fbWithFields(imvKey +: oldFields)) shouldBe 'failure
 
     // https://github.com/ergoplatform/ergo/issues/2114
-    // this fails sporadically, but the mechanism of failure is different from the one further below
-    // TODO: find cause, provide workaround/fix
-    // disabling for now
-    /*
+    // this fails sporadically, when `(imvValue._1.head == 0)`, because less value bytes will be generated
+    // by extensionKvGen(). Workaround is to just generate again while `(imvValue._1.head == 0)`
+    // TODO: document, and possibly rewrite extensionKvGen after the above issues are clarified/solved
+    //       https://github.com/ergoplatform/ergo/issues/2118
+
     // validation of field value sizes
     var imvValue = extensionKvGen(Extension.FieldKeySize, Extension.FieldValueMaxSize + 1).sample.get
-    while (imvValue._1.head == 1) {
+    while (imvValue._1.head == 0) {
         imvValue = extensionKvGen(Extension.FieldKeySize, Extension.FieldValueMaxSize + 1).sample.get
     }
     sc.appendFullBlock(fbWithFields(imvValue +: oldFields)) shouldBe 'failure
-    */
 
     // validation of incorrect interlinks
     val invalidInterlinks = nipopowAlgos.interlinksToExtension(