CBL-6642: Invalid version string error when inserting merged version …

…pushed by active replicator (#2212)

For version vector, the merged versions if exists will appear in the history property of the rev message. The VersionVector class used for parsing the history expects the current version to be together with its merged version in the cv, mv, mv; format.

Replicator/Pusher+Revs.cc

@@ -152,8 +152,11 @@ namespace litecore::repl {
             // Include the document history, but skip the current revision 'cause it's redundant
             alloc_slice history        = request->historyString(doc);
             alloc_slice effectiveRevID = currentReplacementRevID ? currentReplacementRevID : currentRevID;
-            if ( history.hasPrefix(effectiveRevID) && history.size > effectiveRevID.size )
-                msg["history"_sl] = history.from(effectiveRevID.size + 1);
+            if ( history.hasPrefix(effectiveRevID) && history.size > effectiveRevID.size ) {
+                slice historyTruncated = history.from(effectiveRevID.size + 1);
+                while ( historyTruncated.hasPrefix(' ') ) historyTruncated = historyTruncated.from(1);
+                msg["history"_sl] = historyTruncated;
+            }
 
             bool sendLegacyAttachments =
                     (request->legacyAttachments && (revisionFlags & kRevHasAttachments) && !_db->disableBlobSupport());

Replicator/ReplicatorTypes.cc

@@ -98,6 +98,7 @@ namespace litecore::repl {
         historyBuf.reset();
         deltaSrc.reset();
         deltaSrcRevID.reset();
+        _curVersAlloc.reset();
     }
 
     void RevToInsert::trim() {
@@ -108,8 +109,28 @@ namespace litecore::repl {
     vector<C4String> RevToInsert::history() {
         vector<C4String> history;
         history.reserve(10);
-        history.push_back(revID);
-        for ( const void *pos = historyBuf.buf, *end = historyBuf.end(); pos < end; ) {
+
+        // For version vector, the merged versions if exists will appear
+        // in the history property of the rev message. The VersionVector class
+        // used for parsing the history expects the current version to be
+        // together with its merged version in the cv, mv, mv; format.
+        // This code below will check for the merge versions from the history
+        // and put them together with the current version (revID).
+
+        const void* pos = historyBuf.buf;
+        auto        sc  = historyBuf.findByte(';');  // RevTree will not have ';'.
+        if ( sc ) {
+            while ( pos < sc && *(char*)pos == ' ' ) pos = (char*)pos + 1;
+            _curVersAlloc = revID;
+            _curVersAlloc.append(", ");
+            _curVersAlloc.append(slice(pos, sc + 1));
+            history.push_back(_curVersAlloc);
+            pos = (char*)sc + 1;
+        } else {
+            history.push_back(revID);
+        }
+
+        for ( const void* end = historyBuf.end(); pos < end; ) {
             while ( pos < end && *(char*)pos == ' ' ) pos = (char*)pos + 1;
             auto comma = slice(pos, end).findByteOrEnd(',');
             history.push_back(slice(pos, comma));

Replicator/ReplicatorTypes.hh

@@ -110,6 +110,8 @@ namespace litecore::repl {
 
       protected:
         ~RevToInsert() override;
+
+        alloc_slice _curVersAlloc;  // storage used by history();
     };
 
     /** Metadata of a blob to download. */