Add workaround for \v regex metacharacter (fix #713)

CHANGELOG.md

@@ -13,6 +13,7 @@ develop
 
 ### Fixes
 
+- Fix an issue where the regular expression didn't handle `\v` metacharacter correctly.
 - Fix an issue where the selection of encoding menu in toolbar didn't restore to the previous one when encoding reinterpretation was failed.
 - [AppStore ver.] Fix an issue where acknowledgement window was empty.
 

CotEditor/Sources/TextFind.swift

@@ -85,8 +85,18 @@ final class TextFind {
         }
         
         if settings.usesRegularExpression {
+            let sanitizedFindString: String = {
+                // replace `\v` with `\u000b`
+                //   -> Because NSRegularExpression cannot handle `\v` correctly. (2017-07 on macOS 10.12)
+                //   cf. https://github.com/coteditor/CotEditor/issues/713
+                if findString.contains("\\v") {
+                    return findString.replacingOccurrences(of: "(?<!\\\\)\\\\v", with: "\\\\u000b", options: .regularExpression)
+                }
+                return findString
+            }()
+            
             do {
-                self.regex = try NSRegularExpression(pattern: findString, options: settings.regexOptions)
+                self.regex = try NSRegularExpression(pattern: sanitizedFindString, options: settings.regexOptions)
             } catch {
                 let failureReason: String? = (error as? LocalizedError)?.failureReason
                 throw TextFindError.regularExpression(reason: failureReason)

Tests/TextFindTests.swift

@@ -98,6 +98,27 @@ class TextFindTests: XCTestCase {
     }
     
     
+    func testVerticalTabFind() {
+        
+        let text = "\u{b}000\\v000\n"
+        let findString = "\\v"
+        
+        let settings = TextFind.Settings(usesRegularExpression: true,
+                                         isWrap: true,
+                                         regexOptions: [.caseInsensitive],
+                                         unescapesReplacementString: true)
+        
+        let textFind = try! TextFind(for: text, findString: findString, settings: settings)
+        let result = textFind.find(forward: false)
+        XCTAssertEqual(result.count, 1)
+        
+        // wrong pattern with raw NSRegularExpression
+        let regex = try! NSRegularExpression(pattern: findString)
+        let numberOfMatches = regex.numberOfMatches(in: text, range: NSRange(location: 0, length: text.utf16.count))
+        XCTAssertEqual(numberOfMatches, 2)
+    }
+    
+    
     func testSingleRegexFindAndReplacement() {
         
         let findString = "(?!=a)b(c)(?=d)"