fix: deadlock detector, graph/query/lexer бъгове

Поправени проблеми:
- Deadlock detector: cycle reconstruction вече проверява пълен цикъл
- Graph cypher: executeCypher acquire-ва lock при четене
- Graph engine: loadFromFile acquire-ва lock при зареждане
- Graph engine: lock поле е exported за външен достъп
- Query: parseRowData поддържа escape-ване на , и = в стойности
- Query: execUpdateRow escape-ва стойности при сериализация
- Lexer: readNumber спира при втора точка (1.2.3 вече не е валиден float)
- Lexer: skipBlockComment хвърля ValueError при незатворен коментар

292 теста, 0 failure-а.

src/barabadb/core/deadlock.nim

@@ -73,7 +73,14 @@ proc detectCycle*(dd: DeadlockDetector): seq[uint64] =
         while parent.getOrDefault(current, 0'u64) != neighbor and
               parent.getOrDefault(current, 0'u64) != 0:
           current = parent[current]
+          if current == 0: break
           cycle.add(current)
+        # Verify we actually closed the cycle back to neighbor
+        if cycle[^1] != neighbor and parent.getOrDefault(cycle[^1], 0'u64) == neighbor:
+          cycle.add(neighbor)
+        elif cycle[^1] != neighbor:
+          # Incomplete cycle — should not happen with valid parent chain
+          return @[]
         cycle.reverse()
         return cycle
       if neighbor notin visited:

src/barabadb/graph/cypher.nim

@@ -1,6 +1,7 @@
 ## Cypher-like Graph Query Extension for BaraQL
 import std/tables
 import std/strutils
+import std/locks
 import engine
 
 type
@@ -179,6 +180,9 @@ proc executeCypher*(g: Graph, query: CypherQuery): CypherResult =
   if query.pattern.nodes.len == 0:
     return
 
+  acquire(g.lock)
+  defer: release(g.lock)
+
   # Basic MATCH execution
   if query.kind == "MATCH":
     # For each node matching the pattern, collect results

src/barabadb/graph/engine.nim

@@ -38,7 +38,7 @@ type
     reverseAdj*: Table[NodeId, seq[AdjacencyEntry]]  # incoming
     nextNodeId: uint64
     nextEdgeId: uint64
-    lock: Lock
+    lock*: Lock
 
 proc `==`*(a, b: EdgeId): bool = uint64(a) == uint64(b)
 proc `==`*(a, b: NodeId): bool = uint64(a) == uint64(b)
@@ -352,6 +352,7 @@ proc loadFromFile*(path: string): Graph =
     lock: Lock(),
   )
   initLock(result.lock)
+  acquire(result.lock)
 
   for i in 0 ..< nodeCount:
     let id = NodeId(s.readUint64())
@@ -385,4 +386,5 @@ proc loadFromFile*(path: string): Graph =
     result.reverseAdj[dst].add(AdjacencyEntry(edgeId: id, neighbor: src,
                                                weight: weight, label: label))
 
+  release(result.lock)
   s.close()

src/barabadb/query/executor.nim

@@ -406,14 +406,49 @@ proc getValue(values: seq[string], fields: seq[string], colName: string): string
 proc isNull*(value: string): bool =
   value.len == 0 or value.toLower() == "null"
 
+proc escapeRowVal(v: string): string =
+  v.replace("\\", "\\\\").replace(",", "\\,").replace("=", "\\=")
+
+proc unescapeRowVal(v: string): string =
+  result = ""
+  var i = 0
+  while i < v.len:
+    if v[i] == '\\' and i + 1 < v.len:
+      case v[i+1]
+      of '\\', ',', '=':
+        result &= v[i+1]
+        i += 2
+        continue
+      else: discard
+    result &= v[i]
+    inc i
+
 proc parseRowData(valStr: string): Table[string, string] =
   ## Parse "col1=val1,col2=val2" into a table
   result = initTable[string, string]()
-  for part in valStr.split(","):
+  var i = 0
+  var part = ""
+  while i < valStr.len:
+    if valStr[i] == '\\' and i + 1 < valStr.len:
+      part &= valStr[i]
+      part &= valStr[i+1]
+      i += 2
+      continue
+    if valStr[i] == ',':
+      let eqPos = part.find('=')
+      if eqPos >= 0:
+        let k = part[0..<eqPos].strip()
+        let v = unescapeRowVal(part[eqPos+1..^1].strip())
+        result[k] = v
+      part = ""
+    else:
+      part &= valStr[i]
+    inc i
+  if part.len > 0:
     let eqPos = part.find('=')
     if eqPos >= 0:
       let k = part[0..<eqPos].strip()
-      let v = part[eqPos+1..^1].strip()
+      let v = unescapeRowVal(part[eqPos+1..^1].strip())
       result[k] = v
 
 proc executePlan*(ctx: ExecutionContext, plan: IRPlan): seq[Row]
@@ -844,7 +879,7 @@ proc execUpdateRow*(ctx: ExecutionContext, table: string, key: string, sets: Tab
     return 0
   var parts: seq[string] = @[]
   for col, val in parsed:
-    parts.add(col & "=" & val)
+    parts.add(col & "=" & escapeRowVal(val))
   let newVal = parts.join(",")
   # Update indexes: remove old, insert new
   for colName in ctx.btrees.keys.toSeq():

src/barabadb/query/lexer.nim

@@ -363,6 +363,7 @@ proc skipBlockComment(l: var Lexer) =
       discard l.advance()
       return
     discard l.advance()
+  raise newException(ValueError, "Unclosed block comment at line " & $l.line & ", col " & $l.col)
 
 proc readString(l: var Lexer, quote: char): string =
   result = ""
@@ -389,6 +390,8 @@ proc readNumber(l: var Lexer, startLine, startCol: int): Token =
   var isFloat = false
   while l.pos < l.input.len and (l.input[l.pos] in Digits or l.input[l.pos] == '.'):
     if l.input[l.pos] == '.':
+      if isFloat:
+        break  # second dot ends the number
       isFloat = true
     numStr.add(l.input[l.pos])
     discard l.advance()