Handle hash characters (#) in netrc fields (#8109)

Hash symbols were always treated as the beginning of a comment even if
they were in the middle of a username or password. To address this
require some whitespace before a hash character before a comment is
parsed.

That patch also implements support for quoted fields so that passwords
can contain the sequence "foo #bar" without dropping "bar" as a comment.

Issue: #8090

Sources/Basics/Netrc.swift

@@ -132,8 +132,11 @@ public struct NetrcParser {
         let matches = regex.matches(in: text, range: range)
         var trimmedCommentsText = text
         matches.forEach {
-            trimmedCommentsText = trimmedCommentsText
-                .replacingOccurrences(of: nsString.substring(with: $0.range), with: "")
+            let matchedString = nsString.substring(with: $0.range)
+            if !matchedString.starts(with: "\"") {
+                trimmedCommentsText = trimmedCommentsText
+                    .replacingOccurrences(of: matchedString, with: "")
+            }
         }
         return trimmedCommentsText
     }
@@ -151,12 +154,18 @@ private enum RegexUtil {
         case machine, login, password, account, macdef, `default`
 
         func capture(prefix: String = "", in match: NSTextCheckingResult, string: String) -> String? {
-            guard let range = Range(match.range(withName: prefix + rawValue), in: string) else { return nil }
-            return String(string[range])
+            if let quotedRange = Range(match.range(withName: prefix + rawValue + quotedIdentifier), in: string) {
+                return String(string[quotedRange])
+            } else if let range = Range(match.range(withName: prefix + rawValue), in: string) {
+                return String(string[range])
+            } else {
+                return nil
+            }
         }
     }
 
-    static let comments: String = "\\#[\\s\\S]*?.*$"
+    private static let quotedIdentifier = "quoted"
+    static let comments: String = "(\"[^\"]*\"|\\s#.*$)"
     static let `default`: String = #"(?:\s*(?<default>default))"#
     static let accountOptional: String = #"(?:\s*account\s+\S++)?"#
     static let loginPassword: String =
@@ -171,6 +180,6 @@ private enum RegexUtil {
     }
 
     static func namedTrailingCapture(_ string: String, prefix: String = "") -> String {
-        #"\s*\#(string)\s+(?<\#(prefix + string)>\S++)"#
+        #"\s*\#(string)\s+(?:"(?<\#(prefix + string + quotedIdentifier)>[^"]*)"|(?<\#(prefix + string)>\S+))"#
     }
 }

Tests/BasicsTests/NetrcTests.swift

@@ -431,5 +431,84 @@ class NetrcTests: XCTestCase {
         XCTAssertEqual(netrc.machines[1].login, "fred")
         XCTAssertEqual(netrc.machines[1].password, "sunshine4ever")
     }
-}
 
+    func testComments() throws {
+        let content = """
+            # A comment at the beginning of the line
+            machine example.com # Another comment
+            login anonymous  # Another comment
+            password qw#erty  # Another comment
+            """
+
+        let netrc = try NetrcParser.parse(content)
+
+        let machine = netrc.machines.first
+        XCTAssertEqual(machine?.name, "example.com")
+        XCTAssertEqual(machine?.login, "anonymous")
+        XCTAssertEqual(machine?.password, "qw#erty")
+    }
+
+    // TODO: These permutation tests would be excellent swift-testing parameterized tests.
+    func testAllHashQuotingPermutations() throws {
+        let cases = [
+            ("qwerty", "qwerty"),
+            ("qwe#rty", "qwe#rty"),
+            ("\"qwe#rty\"", "qwe#rty"),
+            ("\"qwe #rty\"", "qwe #rty"),
+            ("\"qwe# rty\"", "qwe# rty"),
+        ]
+
+        for (testCase, expected) in cases {
+            let content = """
+                machine example.com
+                login \(testCase)
+                password \(testCase)
+                """
+            let netrc = try NetrcParser.parse(content)
+
+            let machine = netrc.machines.first
+            XCTAssertEqual(machine?.name, "example.com")
+            XCTAssertEqual(machine?.login, expected, "Expected login \(testCase) to parse as \(expected)")
+            XCTAssertEqual(machine?.password, expected, "Expected \(testCase) to parse as \(expected)")
+        }
+    }
+
+    func testAllCommentPermutations() throws {
+        let cases = [
+            ("qwerty   # a comment", "qwerty"),
+            ("qwe#rty   # a comment", "qwe#rty"),
+            ("\"qwe#rty\"   # a comment", "qwe#rty"),
+            ("\"qwe #rty\"   # a comment", "qwe #rty"),
+            ("\"qwe# rty\"   # a comment", "qwe# rty"),
+        ]
+
+        for (testCase, expected) in cases {
+            let content = """
+                machine example.com
+                login \(testCase)
+                password \(testCase)
+                """
+            let netrc = try NetrcParser.parse(content)
+
+            let machine = netrc.machines.first
+            XCTAssertEqual(machine?.name, "example.com")
+            XCTAssertEqual(machine?.login, expected, "Expected login \(testCase) to parse as \(expected)")
+            XCTAssertEqual(machine?.password, expected, "Expected password \(testCase) to parse as \(expected)")
+        }
+    }
+
+    func testQuotedMachine() throws {
+        let content = """
+            machine "example.com"
+            login anonymous
+            password qwerty
+            """
+
+        let netrc = try NetrcParser.parse(content)
+
+        let machine = netrc.machines.first
+        XCTAssertEqual(machine?.name, "example.com")
+        XCTAssertEqual(machine?.login, "anonymous")
+        XCTAssertEqual(machine?.password, "qwerty")
+    }
+}