add contract support for citing posts that have not (yet) been added

ethereum/contracts/core/Forum.sol

@@ -175,6 +175,11 @@ contract Forum is Reputation {
             return amount;
         }
         Post storage post = posts[postId];
+        if (post.authors.length == 0) {
+            // We most likely got here via a citation to a post that hasn't been added yet.
+            // We support this scenario so that a citation graph can be imported one post at a time.
+            return amount;
+        }
         // Propagate negative citations first
         for (uint i = 0; i < post.citations.length; i++) {
             if (post.citations[i].weightPercent < 0) {

ethereum/contracts/core/ValidationPools.sol

@@ -193,7 +193,6 @@ contract ValidationPools is Reputation, Forum {
         // A tie is resolved in favor of the validation pool.
         // This is especially important so that the DAO's first pool can pass,
         // when no reputation has yet been minted.
-
         votePasses =
             stakedFor * pool.params.winRatio[1] >=
             (stakedFor + stakedAgainst) * pool.params.winRatio[0];

ethereum/test/Forum.js

@@ -185,6 +185,20 @@ describe('Forum', () => {
       expect(await dao.balanceOf(account3)).to.equal(200);
     });
 
+    it('should be able to cite a post that has not (yet) been added', async () => {
+      await addPost(account1, 'content-id', []);
+      await addPost(account2, 'second-content-id', [
+        { weightPercent: 10, targetPostId: 'content-id' },
+        { weightPercent: 10, targetPostId: 'nonexistent-content-id' },
+      ]);
+      await initiateValidationPool({ postId: 'second-content-id' });
+      const pool = await dao.validationPools(0);
+      expect(pool.postId).to.equal('second-content-id');
+      await dao.evaluateOutcome(0);
+      expect(await dao.balanceOf(account1)).to.equal(10);
+      expect(await dao.balanceOf(account2)).to.equal(90);
+    });
+
     it('forum reputation rewards are shared with validation pool policing rewards', async () => {
       await addPost(account1, 'content-id', []);
       await initiateValidationPool({ postId: 'content-id' });