Merge pull request #68 from lens-protocol/fix/referral-system

fix: Referral system

contracts/LensHub.sol

@@ -22,7 +22,7 @@ import {LensHubEventHooks} from 'contracts/base/LensHubEventHooks.sol';
 
 // Libraries
 import {ActionLib} from 'contracts/libraries/ActionLib.sol';
-import {CollectLib} from 'contracts/libraries/CollectLib.sol';
+import {LegacyCollectLib} from 'contracts/libraries/LegacyCollectLib.sol';
 import {FollowLib} from 'contracts/libraries/FollowLib.sol';
 import {GovernanceLib} from 'contracts/libraries/GovernanceLib.sol';
 import {MetaTxLib} from 'contracts/libraries/MetaTxLib.sol';
@@ -440,7 +440,7 @@ contract LensHub is
         returns (uint256)
     {
         return
-            CollectLib.collect({
+            LegacyCollectLib.collect({
                 collectParams: collectParams,
                 transactionExecutor: msg.sender,
                 collectorProfileOwner: ownerOf(collectParams.collectorProfileId),
@@ -459,9 +459,9 @@ contract LensHub is
         onlyProfileOwnerOrDelegatedExecutor(signature.signer, collectParams.collectorProfileId)
         returns (uint256)
     {
-        MetaTxLib.validateCollectSignature(signature, collectParams);
+        MetaTxLib.validateLegacyCollectSignature(signature, collectParams);
         return
-            CollectLib.collect({
+            LegacyCollectLib.collect({
                 collectParams: collectParams,
                 transactionExecutor: signature.signer,
                 collectorProfileOwner: ownerOf(collectParams.collectorProfileId),

contracts/libraries/CollectLib.sol

@@ -1,193 +0,0 @@
-// SPDX-License-Identifier: MIT
-
-pragma solidity ^0.8.15;
-
-import {ValidationLib} from 'contracts/libraries/ValidationLib.sol';
-import {Types} from 'contracts/libraries/constants/Types.sol';
-import {Errors} from 'contracts/libraries/constants/Errors.sol';
-import {Events} from 'contracts/libraries/constants/Events.sol';
-import {ICollectNFT} from 'contracts/interfaces/ICollectNFT.sol';
-import {ICollectModule} from 'contracts/interfaces/ICollectModule.sol';
-import {ILegacyCollectModule} from 'contracts/interfaces/ILegacyCollectModule.sol';
-import {Clones} from '@openzeppelin/contracts/proxy/Clones.sol';
-import {Strings} from '@openzeppelin/contracts/utils/Strings.sol';
-import {StorageLib} from 'contracts/libraries/StorageLib.sol';
-
-/**
- * @title CollectLib
- * @author Lens Protocol
- */
-library CollectLib {
-    using Strings for uint256;
-
-    string constant COLLECT_NFT_NAME_INFIX = '-Collect-';
-    string constant COLLECT_NFT_SYMBOL_INFIX = '-Cl-';
-
-    function collect(
-        Types.CollectParams calldata collectParams,
-        address transactionExecutor,
-        address collectorProfileOwner,
-        address collectNFTImpl
-    ) external returns (uint256) {
-        ValidationLib.validateNotBlocked({
-            profile: collectParams.collectorProfileId,
-            byProfile: collectParams.publicationCollectedProfileId
-        });
-
-        address collectModule;
-        Types.PublicationType[] memory referrerPubTypes;
-        uint256 tokenId;
-        address collectNFT;
-        {
-            Types.Publication storage _collectedPublication = StorageLib.getPublication(
-                collectParams.publicationCollectedProfileId,
-                collectParams.publicationCollectedId
-            );
-            collectModule = _collectedPublication.__DEPRECATED__collectModule;
-            if (collectModule == address(0)) {
-                // Doesn't have collectModule, thus it cannot be collected (a mirror or non-existent).
-                revert Errors.CollectNotAllowed();
-            }
-
-            referrerPubTypes = ValidationLib.validateReferrersAndGetReferrersPubTypes(
-                collectParams.referrerProfileIds,
-                collectParams.referrerPubIds,
-                collectParams.publicationCollectedProfileId,
-                collectParams.publicationCollectedId
-            );
-            collectNFT = _getOrDeployCollectNFT(
-                _collectedPublication,
-                collectParams.publicationCollectedProfileId,
-                collectParams.publicationCollectedId,
-                collectNFTImpl
-            );
-            tokenId = ICollectNFT(collectNFT).mint(collectorProfileOwner);
-        }
-
-        _processCollect(
-            collectParams,
-            ProcessCollectParams({
-                transactionExecutor: transactionExecutor,
-                collectorProfileOwner: collectorProfileOwner,
-                referrerPubTypes: referrerPubTypes,
-                collectModule: collectModule
-            })
-        );
-
-        emit Events.Collected({
-            collectActionParams: Types.ProcessActionParams({
-                publicationActedProfileId: collectParams.publicationCollectedProfileId,
-                publicationActedId: collectParams.publicationCollectedId,
-                actorProfileId: collectParams.collectorProfileId,
-                actorProfileOwner: collectorProfileOwner,
-                transactionExecutor: transactionExecutor,
-                referrerProfileIds: collectParams.referrerProfileIds,
-                referrerPubIds: collectParams.referrerPubIds,
-                referrerPubTypes: referrerPubTypes,
-                actionModuleData: collectParams.collectModuleData
-            }),
-            collectModule: collectModule,
-            collectNFT: collectNFT,
-            tokenId: tokenId,
-            collectActionResult: '',
-            timestamp: block.timestamp
-        });
-
-        return tokenId;
-    }
-
-    function _getOrDeployCollectNFT(
-        Types.Publication storage _collectedPublication,
-        uint256 publicationCollectedProfileId,
-        uint256 publicationCollectedId,
-        address collectNFTImpl
-    ) private returns (address) {
-        address collectNFT = _collectedPublication.__DEPRECATED__collectNFT;
-        if (collectNFT == address(0)) {
-            collectNFT = _deployCollectNFT(publicationCollectedProfileId, publicationCollectedId, collectNFTImpl);
-            _collectedPublication.__DEPRECATED__collectNFT = collectNFT;
-        }
-        return collectNFT;
-    }
-
-    // Stack too deep, so we need to use a struct.
-    struct ProcessCollectParams {
-        address transactionExecutor;
-        address collectorProfileOwner;
-        Types.PublicationType[] referrerPubTypes;
-        address collectModule;
-    }
-
-    function _processCollect(
-        Types.CollectParams calldata collectParams,
-        ProcessCollectParams memory processCollectParams
-    ) private {
-        try
-            ICollectModule(processCollectParams.collectModule).processCollect(
-                Types.ProcessCollectParams({
-                    publicationCollectedProfileId: collectParams.publicationCollectedProfileId,
-                    publicationCollectedId: collectParams.publicationCollectedId,
-                    collectorProfileId: collectParams.collectorProfileId,
-                    collectorProfileOwner: processCollectParams.collectorProfileOwner,
-                    transactionExecutor: processCollectParams.transactionExecutor,
-                    referrerProfileIds: collectParams.referrerProfileIds,
-                    referrerPubIds: collectParams.referrerPubIds,
-                    referrerPubTypes: processCollectParams.referrerPubTypes,
-                    data: collectParams.collectModuleData
-                })
-            )
-        {} catch (bytes memory err) {
-            assembly {
-                // Equivalent to reverting with the returned error selector if
-                // the length is not zero.
-                let length := mload(err)
-                if iszero(iszero(length)) {
-                    revert(add(err, 32), length)
-                }
-            }
-            uint256 referrerProfileId;
-            uint256 referrerPubId;
-            if (collectParams.referrerProfileIds.length > 0) {
-                if (collectParams.referrerProfileIds.length > 1) {
-                    // Deprecated modules only support one referrer.
-                    revert Errors.DeprecaredModulesOnlySupportOneReferrer();
-                }
-                // Only one referral was passed.
-                referrerProfileId = collectParams.referrerProfileIds[0];
-                referrerPubId = collectParams.referrerPubIds[0];
-            }
-            ILegacyCollectModule(processCollectParams.collectModule).processCollect(
-                collectParams.publicationCollectedProfileId,
-                processCollectParams.transactionExecutor,
-                referrerProfileId,
-                referrerPubId,
-                collectParams.collectModuleData
-            );
-        }
-    }
-
-    /**
-     * @notice Deploys the given profile's Collect NFT contract.
-     *
-     * @param profileId The token ID of the profile which Collect NFT should be deployed.
-     * @param pubId The publication ID of the publication being collected, which Collect NFT should be deployed.
-     * @param collectNFTImpl The address of the Collect NFT implementation that should be used for the deployment.
-     *
-     * @return address The address of the deployed Collect NFT contract.
-     */
-    function _deployCollectNFT(uint256 profileId, uint256 pubId, address collectNFTImpl) private returns (address) {
-        address collectNFT = Clones.clone(collectNFTImpl);
-
-        string memory collectNFTName = string(
-            abi.encodePacked(profileId.toString(), COLLECT_NFT_NAME_INFIX, pubId.toString())
-        );
-        string memory collectNFTSymbol = string(
-            abi.encodePacked(profileId.toString(), COLLECT_NFT_SYMBOL_INFIX, pubId.toString())
-        );
-
-        ICollectNFT(collectNFT).initialize(profileId, pubId, collectNFTName, collectNFTSymbol);
-        emit Events.CollectNFTDeployed(profileId, pubId, collectNFT, block.timestamp);
-
-        return collectNFT;
-    }
-}

contracts/libraries/LegacyCollectLib.sol

@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.15;
+
+import {ValidationLib} from 'contracts/libraries/ValidationLib.sol';
+import {Types} from 'contracts/libraries/constants/Types.sol';
+import {Errors} from 'contracts/libraries/constants/Errors.sol';
+import {Events} from 'contracts/libraries/constants/Events.sol';
+import {ICollectNFT} from 'contracts/interfaces/ICollectNFT.sol';
+import {ICollectModule} from 'contracts/interfaces/ICollectModule.sol';
+import {ILegacyCollectModule} from 'contracts/interfaces/ILegacyCollectModule.sol';
+import {Clones} from '@openzeppelin/contracts/proxy/Clones.sol';
+import {Strings} from '@openzeppelin/contracts/utils/Strings.sol';
+import {StorageLib} from 'contracts/libraries/StorageLib.sol';
+import {PublicationLib} from 'contracts/libraries/PublicationLib.sol';
+
+/**
+ * @title LegacyCollectLib
+ * @author Lens Protocol
+ * @notice Library containing the logic for legacy collect operation.
+ */
+library LegacyCollectLib {
+    using Strings for uint256;
+
+    string constant COLLECT_NFT_NAME_INFIX = '-Collect-';
+    string constant COLLECT_NFT_SYMBOL_INFIX = '-Cl-';
+
+    /**
+     * @dev Emitted upon a successful legacy collect action.
+     *
+     * @param publicationCollectedProfileId The profile ID of the publication being collected.
+     * @param publicationCollectedId The publication ID of the publication being collected.
+     * @param transactionExecutor The address of the account that executed the collect transaction.
+     * @param referrerProfileId The profile ID of the referrer, if any. Zero if no referrer.
+     * @param referrerPubId The publication ID of the referrer, if any. Zero if no referrer.
+     * @param collectModuleData The data passed to the collect module's collect action. This is ABI-encoded and depends
+     * on the collect module chosen.
+     * @param timestamp The current block timestamp.
+     */
+    event CollectedLegacy(
+        uint256 indexed publicationCollectedProfileId,
+        uint256 indexed publicationCollectedId,
+        address transactionExecutor,
+        uint256 referrerProfileId,
+        uint256 referrerPubId,
+        bytes collectModuleData,
+        uint256 timestamp
+    );
+
+    function collect(
+        Types.CollectParams calldata collectParams,
+        address transactionExecutor,
+        address collectorProfileOwner,
+        address collectNFTImpl
+    ) external returns (uint256) {
+        ValidationLib.validateNotBlocked({
+            profile: collectParams.collectorProfileId,
+            byProfile: collectParams.publicationCollectedProfileId
+        });
+
+        address collectModule;
+        uint256 tokenId;
+        address collectNFT;
+        {
+            Types.Publication storage _collectedPublication = StorageLib.getPublication(
+                collectParams.publicationCollectedProfileId,
+                collectParams.publicationCollectedId
+            );
+            // This is a legacy collect operation, so we get the collect module from the deprecated storage field.
+            collectModule = _collectedPublication.__DEPRECATED__collectModule;
+            if (collectModule == address(0)) {
+                // It doesn't have collect module, thus it cannot be collected (a mirror or non-existent).
+                revert Errors.CollectNotAllowed();
+            }
+
+            if (collectParams.referrerProfileId != 0 || collectParams.referrerPubId != 0) {
+                ValidationLib.validateLegacyCollectReferrer(
+                    collectParams.referrerProfileId,
+                    collectParams.referrerPubId,
+                    collectParams.publicationCollectedProfileId,
+                    collectParams.publicationCollectedId
+                );
+            }
+
+            collectNFT = _getOrDeployCollectNFT(
+                _collectedPublication,
+                collectParams.publicationCollectedProfileId,
+                collectParams.publicationCollectedId,
+                collectNFTImpl
+            );
+            tokenId = ICollectNFT(collectNFT).mint(collectorProfileOwner);
+        }
+
+        ILegacyCollectModule(collectModule).processCollect({
+            // Legacy collect modules expect referrer profile ID to match the collected pub's author if no referrer set.
+            referrerProfileId: collectParams.referrerProfileId == 0
+                ? collectParams.publicationCollectedProfileId
+                : collectParams.referrerProfileId,
+            // Collect NFT is minted to the `collectorProfileOwner`. Some follow-based constraints are expected to be
+            // broken in legacy collect modules if the `transactionExecutor` does not match the `collectorProfileOwner`.
+            collector: transactionExecutor,
+            profileId: collectParams.publicationCollectedProfileId,
+            pubId: collectParams.publicationCollectedId,
+            data: collectParams.collectModuleData
+        });
+
+        emit CollectedLegacy({
+            publicationCollectedProfileId: collectParams.publicationCollectedProfileId,
+            publicationCollectedId: collectParams.publicationCollectedId,
+            transactionExecutor: transactionExecutor,
+            referrerProfileId: collectParams.referrerProfileId,
+            referrerPubId: collectParams.referrerPubId,
+            collectModuleData: collectParams.collectModuleData,
+            timestamp: block.timestamp
+        });
+
+        return tokenId;
+    }
+
+    function _getOrDeployCollectNFT(
+        Types.Publication storage _collectedPublication,
+        uint256 publicationCollectedProfileId,
+        uint256 publicationCollectedId,
+        address collectNFTImpl
+    ) private returns (address) {
+        address collectNFT = _collectedPublication.__DEPRECATED__collectNFT;
+        if (collectNFT == address(0)) {
+            collectNFT = _deployCollectNFT(publicationCollectedProfileId, publicationCollectedId, collectNFTImpl);
+            _collectedPublication.__DEPRECATED__collectNFT = collectNFT;
+        }
+        return collectNFT;
+    }
+
+    /**
+     * @notice Deploys the given profile's Collect NFT contract.
+     *
+     * @param profileId The token ID of the profile which Collect NFT should be deployed.
+     * @param pubId The publication ID of the publication being collected, which Collect NFT should be deployed.
+     * @param collectNFTImpl The address of the Collect NFT implementation that should be used for the deployment.
+     *
+     * @return address The address of the deployed Collect NFT contract.
+     */
+    function _deployCollectNFT(uint256 profileId, uint256 pubId, address collectNFTImpl) private returns (address) {
+        address collectNFT = Clones.clone(collectNFTImpl);
+
+        string memory collectNFTName = string(
+            abi.encodePacked(profileId.toString(), COLLECT_NFT_NAME_INFIX, pubId.toString())
+        );
+        string memory collectNFTSymbol = string(
+            abi.encodePacked(profileId.toString(), COLLECT_NFT_SYMBOL_INFIX, pubId.toString())
+        );
+
+        ICollectNFT(collectNFT).initialize(profileId, pubId, collectNFTName, collectNFTSymbol);
+        emit Events.CollectNFTDeployed(profileId, pubId, collectNFT, block.timestamp);
+
+        return collectNFT;
+    }
+}

contracts/libraries/MetaTxLib.sol

@@ -398,7 +398,7 @@ library MetaTxLib {
         );
     }
 
-    function validateCollectSignature(
+    function validateLegacyCollectSignature(
         Types.EIP712Signature calldata signature,
         Types.CollectParams calldata collectParams
     ) external {
@@ -406,12 +406,12 @@ library MetaTxLib {
             _calculateDigest(
                 keccak256(
                     abi.encode(
-                        Typehash.COLLECT,
+                        Typehash.LEGACY_COLLECT,
                         collectParams.publicationCollectedProfileId,
                         collectParams.publicationCollectedId,
                         collectParams.collectorProfileId,
-                        collectParams.referrerProfileIds,
-                        collectParams.referrerPubIds,
+                        collectParams.referrerProfileId,
+                        collectParams.referrerPubId,
                         keccak256(collectParams.collectModuleData),
                         _getAndIncrementNonce(signature.signer),
                         signature.deadline

contracts/libraries/PublicationLib.sol

@@ -259,7 +259,7 @@ library PublicationLib {
     }
 
     function _fillReferencePublicationStorage(
-        Types.ReferencePubParams memory referencePubParams,
+        Types.ReferencePubParams calldata referencePubParams,
         Types.PublicationType referencePubType
     ) private returns (uint256) {
         uint256 pubIdAssigned = ++StorageLib.getProfile(referencePubParams.profileId).pubCount;
@@ -273,14 +273,20 @@ library PublicationLib {
             referencePubParams.pointedProfileId,
             referencePubParams.pointedPubId
         );
-        if (_pubPointed.pubType == Types.PublicationType.Post) {
+        Types.PublicationType pubPointedType = _pubPointed.pubType;
+        if (pubPointedType == Types.PublicationType.Post) {
+            // The publication pointed is a Lens V2 post.
             _referencePub.rootProfileId = referencePubParams.pointedProfileId;
             _referencePub.rootPubId = referencePubParams.pointedPubId;
-        } else {
-            // The publication pointed is either a comment or a quote.
+        } else if (pubPointedType == Types.PublicationType.Comment || pubPointedType == Types.PublicationType.Quote) {
+            // The publication pointed is either a Lens V2 comment or a Lens V2 quote.
+            // Note that even when the publication pointed is a V2 one, it will lack `rootProfileId` and `rootPubId` if
+            // there is a Lens V1 Legacy publication in the thread of interactions (including the root post itself).
             _referencePub.rootProfileId = _pubPointed.rootProfileId;
             _referencePub.rootPubId = _pubPointed.rootPubId;
         }
+        // Otherwise the root is not filled, as the pointed publication is a Lens V1 Legacy publication, which does not
+        // support Lens V2 referral system.
         return pubIdAssigned;
     }
 

contracts/libraries/ValidationLib.sol

@@ -87,8 +87,8 @@ library ValidationLib {
     function validateReferrersAndGetReferrersPubTypes(
         uint256[] memory referrerProfileIds,
         uint256[] memory referrerPubIds,
-        uint256 profileId,
-        uint256 pubId
+        uint256 targetedProfileId,
+        uint256 targetedPubId
     ) internal view returns (Types.PublicationType[] memory) {
         if (referrerProfileIds.length != referrerPubIds.length) {
             revert Errors.ArrayMismatch();
@@ -105,8 +105,8 @@ library ValidationLib {
             referrerPubTypes[i] = _validateReferrerAndGetReferrerPubType(
                 referrerProfileId,
                 referrerPubId,
-                profileId,
-                pubId
+                targetedProfileId,
+                targetedPubId
             );
             unchecked {
                 i++;
@@ -115,15 +115,34 @@ library ValidationLib {
         return referrerPubTypes;
     }
 
+    function validateLegacyCollectReferrer(
+        uint256 referrerProfileId,
+        uint256 referrerPubId,
+        uint256 publicationCollectedProfileId,
+        uint256 publicationCollectedId
+    ) external view {
+        if (PublicationLib.getPublicationType(referrerProfileId, referrerPubId) != Types.PublicationType.Mirror) {
+            revert Errors.InvalidReferrer();
+        }
+        _validateReferrerAsMirror(
+            referrerProfileId,
+            referrerPubId,
+            publicationCollectedProfileId,
+            publicationCollectedId
+        );
+    }
+
     function _validateReferrerAndGetReferrerPubType(
         uint256 referrerProfileId,
         uint256 referrerPubId,
-        uint256 profileId,
-        uint256 pubId
+        uint256 targetedProfileId,
+        uint256 targetedPubId
     ) private view returns (Types.PublicationType) {
         if (referrerPubId == 0) {
             // Unchecked/Unverified referral. Profile referrer, not attached to a publication.
-            if (StorageLib.getTokenData(referrerProfileId).owner == address(0) || referrerProfileId == profileId) {
+            if (
+                StorageLib.getTokenData(referrerProfileId).owner == address(0) || referrerProfileId == targetedProfileId
+            ) {
                 revert Errors.InvalidReferrer();
             }
             return Types.PublicationType.Nonexistent;
@@ -131,19 +150,19 @@ library ValidationLib {
             // Checked/Verified referral. Publication referrer.
             if (
                 // Cannot pass itself as a referrer.
-                referrerProfileId == profileId && referrerPubId == pubId
+                referrerProfileId == targetedProfileId && referrerPubId == targetedPubId
             ) {
                 revert Errors.InvalidReferrer();
             }
             Types.PublicationType referrerPubType = PublicationLib.getPublicationType(referrerProfileId, referrerPubId);
             if (referrerPubType == Types.PublicationType.Mirror) {
-                _validateReferrerAsMirror(referrerProfileId, referrerPubId, profileId, pubId);
+                _validateReferrerAsMirror(referrerProfileId, referrerPubId, targetedProfileId, targetedPubId);
             } else if (
                 referrerPubType == Types.PublicationType.Comment || referrerPubType == Types.PublicationType.Quote
             ) {
-                _validateReferrerAsCommentOrQuote(referrerProfileId, referrerPubId, profileId, pubId);
+                _validateReferrerAsCommentOrQuote(referrerProfileId, referrerPubId, targetedProfileId, targetedPubId);
             } else if (referrerPubType == Types.PublicationType.Post) {
-                _validateReferrerAsPost(referrerProfileId, referrerPubId, profileId, pubId);
+                _validateReferrerAsPost(referrerProfileId, referrerPubId, targetedProfileId, targetedPubId);
             } else {
                 revert Errors.InvalidReferrer();
             }
@@ -154,16 +173,13 @@ library ValidationLib {
     function _validateReferrerAsPost(
         uint256 referrerProfileId,
         uint256 referrerPubId,
-        uint256 profileId,
-        uint256 pubId
+        uint256 targetedProfileId,
+        uint256 targetedPubId
     ) private view {
-        Types.Publication storage _publication = StorageLib.getPublication(profileId, pubId);
-        if (
-            // Publication being collected/referenced is not pointing to the referrer post and...
-            (_publication.pointedProfileId != referrerProfileId || _publication.pointedPubId != referrerPubId) &&
-            // ...publication being collected/referenced does not have the referrer post as the root.
-            (_publication.rootProfileId != referrerProfileId || _publication.rootPubId != referrerPubId)
-        ) {
+        Types.Publication storage _targetedPub = StorageLib.getPublication(targetedProfileId, targetedPubId);
+        // Publication targeted must have the referrer post as the root. This enables the use case of rewarding the
+        // root publication for an action over any of its descendants.
+        if (_targetedPub.rootProfileId != referrerProfileId || _targetedPub.rootPubId != referrerPubId) {
             revert Errors.InvalidReferrer();
         }
     }
@@ -171,13 +187,13 @@ library ValidationLib {
     function _validateReferrerAsMirror(
         uint256 referrerProfileId,
         uint256 referrerPubId,
-        uint256 profileId,
-        uint256 pubId
+        uint256 targetedProfileId,
+        uint256 targetedPubId
     ) private view {
         Types.Publication storage _referrerMirror = StorageLib.getPublication(referrerProfileId, referrerPubId);
         if (
             // A mirror can only be a referrer of a publication if it is pointing to it.
-            _referrerMirror.pointedProfileId != profileId || _referrerMirror.pointedPubId != pubId
+            _referrerMirror.pointedProfileId != targetedProfileId || _referrerMirror.pointedPubId != targetedPubId
         ) {
             revert Errors.InvalidReferrer();
         }
@@ -188,30 +204,35 @@ library ValidationLib {
      *
      * @param referrerProfileId The profile id of the referrer.
      * @param referrerPubId The publication id of the referrer.
-     * @param profileId This is the ID of the profile who authored the publication being collected or referenced.
-     * @param pubId This is the pub user collects or references.
+     * @param targetedProfileId The ID of the profile who authored the publication being acted or referenced.
+     * @param targetedPubId The pub ID being acted or referenced.
      */
     function _validateReferrerAsCommentOrQuote(
         uint256 referrerProfileId,
         uint256 referrerPubId,
-        uint256 profileId,
-        uint256 pubId
+        uint256 targetedProfileId,
+        uint256 targetedPubId
     ) private view {
         Types.Publication storage _referrerPub = StorageLib.getPublication(referrerProfileId, referrerPubId);
-        Types.PublicationType typeOfPubPointedByReferrer = PublicationLib.getPublicationType(profileId, pubId);
-        // We already know that the publication being collected/referenced is not a mirror nor a non-existent one.
-        if (typeOfPubPointedByReferrer == Types.PublicationType.Post) {
-            // If the publication collected/referenced is a post, the referrer comment/quote must have it as the root.
-            if (_referrerPub.rootProfileId != profileId || _referrerPub.rootPubId != pubId) {
+        Types.PublicationType typeOfTargetedPub = PublicationLib.getPublicationType(targetedProfileId, targetedPubId);
+        // We already know that the publication being acted/referenced is not a mirror nor a non-existent one.
+        if (typeOfTargetedPub == Types.PublicationType.Post) {
+            // If the publication acted/referenced is a post, the referrer comment/quote must have it as the root.
+            if (_referrerPub.rootProfileId != targetedProfileId || _referrerPub.rootPubId != targetedPubId) {
                 revert Errors.InvalidReferrer();
             }
         } else {
-            // The publication collected/referenced is a comment or a quote.
-            Types.Publication storage _pubPointedByReferrer = StorageLib.getPublication(profileId, pubId);
-            // The referrer publication and the collected/referenced publication must share the same root.
+            // The publication acted/referenced is a comment or a quote.
+            Types.Publication storage _targetedPub = StorageLib.getPublication(targetedProfileId, targetedPubId);
             if (
-                _referrerPub.rootProfileId != _pubPointedByReferrer.rootProfileId ||
-                _referrerPub.rootPubId != _pubPointedByReferrer.rootPubId
+                // Targeted pub must be a "pure" Lens V2 comment/quote, which means there is no Lens V1 Legacy comment
+                // or post on its tree of interactions, and its root pub is filled.
+                // Otherwise, two Lens V2 "non-pure" publications could be passed as a referrer to each other,
+                // even without having any interaction in common.
+                _targetedPub.rootPubId == 0 ||
+                // The referrer publication and the acted/referenced publication must share the same root.
+                _referrerPub.rootProfileId != _targetedPub.rootProfileId ||
+                _referrerPub.rootPubId != _targetedPub.rootPubId
             ) {
                 revert Errors.InvalidReferrer();
             }

contracts/libraries/constants/Errors.sol

@@ -27,7 +27,6 @@ library Errors {
     error NotFollowing();
     error SelfFollow();
     error InvalidReferrer();
-    error DeprecaredModulesOnlySupportOneReferrer();
     error InvalidPointedPub();
     error NonERC721ReceiverImplementer();
 
@@ -38,7 +37,7 @@ library Errors {
     error InitParamsInvalid();
     error ActionNotAllowed();
 
-    error CollectNotAllowed(); // Used in CollectLib (pending deprecation)
+    error CollectNotAllowed(); // Used in LegacyCollectLib (pending deprecation)
 
     // MultiState Errors
     error Paused();

contracts/libraries/constants/Typehash.sol

@@ -10,7 +10,7 @@ library Typehash {
 
     bytes32 constant CHANGE_DELEGATED_EXECUTORS_CONFIG = keccak256('ChangeDelegatedExecutorsConfig(uint256 delegatorProfileId,address[] delegatedExecutors,bool[] approvals,uint64 configNumber,bool switchToGivenConfig,uint256 nonce,uint256 deadline)');
 
-    bytes32 constant COLLECT = keccak256('Collect(uint256 publicationCollectedProfileId,uint256 publicationCollectedId,uint256 collectorProfileId,uint256[] referrerProfileIds,uint256[] referrerPubIds,bytes collectModuleData,uint256 nonce,uint256 deadline)');
+    bytes32 constant LEGACY_COLLECT = keccak256('Collect(uint256 publicationCollectedProfileId,uint256 publicationCollectedId,uint256 collectorProfileId,uint256 referrerProfileId,uint256 referrerPubId,bytes collectModuleData,uint256 nonce,uint256 deadline)');
 
     bytes32 constant COMMENT = keccak256('Comment(uint256 profileId,string contentURI,uint256 pointedProfileId,uint256 pointedPubId,uint256[] referrerProfileIds,uint256[] referrerPubIds,bytes referenceModuleData,address collectModule,bytes collectModuleInitData,address referenceModule,bytes referenceModuleInitData,uint256 nonce,uint256 deadline)');
 

contracts/libraries/constants/Types.sol

@@ -261,21 +261,22 @@ library Types {
 
     /**
      * Deprecated in V2: Will be removed after some time after upgrading to V2.
-     * @notice A struct containing the parameters required for the `collect()` function.
+     * @notice A struct containing the parameters required for the legacy `collect()` function.
+     * @dev The referrer can only be a mirror of the publication being collected.
      *
      * @param publicationCollectedProfileId The token ID of the profile that published the publication to collect.
      * @param publicationCollectedId The publication to collect's publication ID.
      * @param collectorProfileId The collector profile.
-     * @param referrerProfileId
-     * @param referrerPubId
+     * @param referrerProfileId The ID of a profile that authored a mirror that helped discovering the collected pub.
+     * @param referrerPubId The ID of the mirror that helped discovering the collected pub.
      * @param collectModuleData The arbitrary data to pass to the collectModule if needed.
      */
     struct CollectParams {
         uint256 publicationCollectedProfileId;
         uint256 publicationCollectedId;
         uint256 collectorProfileId;
-        uint256[] referrerProfileIds;
-        uint256[] referrerPubIds;
+        uint256 referrerProfileId;
+        uint256 referrerPubId;
         bytes collectModuleData;
     }
 

foundry.toml

@@ -6,7 +6,7 @@ test = 'test/foundry'
 cache_path  = 'forge-cache'
 fs_permissions = [{ access = "read-write", path = "./"}]
 optimizer = true
-optimizer_runs = 65
+optimizer_runs = 10
 ignored_error_codes = []
 
 [rpc_endpoints]

test/foundry/fork/UpgradeForkTest.t.sol

@@ -311,8 +311,8 @@ contract UpgradeForkTest is BaseTest {
                     publicationCollectedProfileId: profileId,
                     publicationCollectedId: 1,
                     collectorProfileId: profileId,
-                    referrerProfileIds: _emptyUint256Array(),
-                    referrerPubIds: _emptyUint256Array(),
+                    referrerProfileId: 0,
+                    referrerPubId: 0,
                     collectModuleData: ''
                 })
             );
@@ -321,8 +321,8 @@ contract UpgradeForkTest is BaseTest {
                     publicationCollectedProfileId: profileId,
                     publicationCollectedId: 2,
                     collectorProfileId: profileId,
-                    referrerProfileIds: _emptyUint256Array(),
-                    referrerPubIds: _emptyUint256Array(),
+                    referrerProfileId: 0,
+                    referrerPubId: 0,
                     collectModuleData: ''
                 })
             );
@@ -331,8 +331,8 @@ contract UpgradeForkTest is BaseTest {
                     publicationCollectedProfileId: profileId,
                     publicationCollectedId: 3,
                     collectorProfileId: profileId,
-                    referrerProfileIds: _emptyUint256Array(),
-                    referrerPubIds: _emptyUint256Array(),
+                    referrerProfileId: 0,
+                    referrerPubId: 0,
                     collectModuleData: ''
                 })
             );