Fix miniStream iteration bug, add HWP test (#5)

The sector data truncation logic was checking the constant value passed to the `oleStream` function, instead of the incremented iteration index.

Resolves #1.

Author: MaxDesiatov

Sources/OLEKit/OLEStream.swift

@@ -59,7 +59,7 @@ extension Reader {
       // if sector is the last of the file, sometimes it is not a
       // complete sector (of 512 or 4K), so we may read less than
       // sectorsize.
-      if sectorID == fat.count - 1 {
+      if currentSectorID == fat.count - 1 {
         data.append(readDataToEnd())
       } else {
         data.append(readData(ofLength: Int(sectorSize)))

Tests/OLEKitTests/OLEKitTests.swift

@@ -100,4 +100,16 @@ final class OLEKitTests: XCTestCase {
       "\u{05}DocumentSummaryInformation",
     ])
   }
+
+  func testHWP() throws {
+    let url = URL(fileURLWithPath: #file)
+      .deletingLastPathComponent()
+      .appendingPathComponent("blank.hwp")
+    let ole = try OLEFile(url.path)
+    let fileHeaderStream = ole.root.children.first(where: { $0.name == "FileHeader" })!
+    let reader = try ole.stream(fileHeaderStream)
+    let data = reader.readData(ofLength: 32)
+    let signature = String(data: data, encoding: .ascii)
+    XCTAssertEqual(signature, "HWP Document File\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0")
+  }
 }