The paste helper tests were broken because of the change to escape tabs. This exposed a few bugs:

- Tabs should be expanded to spaces before being escaped with backslashes
- Do not double-escape with backslash and ^V. Prefer ^V.

This commit also fixes the tests by adding tab escapes where needed.

iTerm2XCTests/iTermPasteHelperTest.m

@@ -139,7 +139,7 @@ static const double kFloatingPointTolerance = 0.00001;
 - (void)testSanitizeEscapeSpecialCharacters {
     [self sanitizeString:kTestString
-                  expect:@"a\\ \\(\t\r\r\n" @"\x16" @"“”‘’–—b"
+                  expect:@"a\\ \\(\\\t\r\r\n" @"\x16" @"“”‘’–—b"
                    flags:kPasteFlagsEscapeSpecialCharacters
             tabTransform:kTabTransformNone
             spacesPerTab:0];
@@ -186,7 +186,7 @@ static const double kFloatingPointTolerance = 0.00001;
 }
 - (void)testSanitizeAllFlagsOn {
-    NSString *expectedString = @"a\\ \\(\t\r\r\\\"\\\"\\'\\'--b";
+    NSString *expectedString = @"a\\ \\(\\\t\r\r\\\"\\\"\\'\\'--b";
     NSData *data = [expectedString dataUsingEncoding:NSUTF8StringEncoding];
     NSString *expected = [data stringWithBase64EncodingWithLineBreak:@"\r"];
     [self sanitizeString:kTestString
@@ -242,6 +242,30 @@ static const double kFloatingPointTolerance = 0.00001;
     XCTAssert([_writeBuffer isEqualToString:expected]);
 }
+- (void)testExpandTabsBeforeEscaping {
+    [_helper pasteString:@"\t"
+                  slowly:NO
+        escapeShellChars:YES
+                commands:NO
+            tabTransform:kTabTransformConvertToSpaces
+            spacesPerTab:4];
+    [self runTimer];
+    NSString *expected = @"\\ \\ \\ \\ ";
+    XCTAssert([_writeBuffer isEqualToString:expected]);
+}
+
+- (void)testEscapeDoesNotEscapeCarriageReturn {
+    [_helper pasteString:@"\r"
+                  slowly:NO
+        escapeShellChars:YES
+                commands:NO
+            tabTransform:kTabTransformConvertToSpaces
+            spacesPerTab:4];
+    [self runTimer];
+    NSString *expected = @"\r";
+    XCTAssert([_writeBuffer isEqualToString:expected]);
+}
+
 - (void)testPasteStringWithFlagsAndConvertToSpacesTabTransform {
     [_helper pasteString:kTestString
                   slowly:NO
@@ -250,7 +274,31 @@ static const double kFloatingPointTolerance = 0.00001;
             tabTransform:kTabTransformConvertToSpaces
             spacesPerTab:4];
     [self runTimer];
-    NSString *expected = @"a\\ \\(    \r\r“”‘’–—b";
+    NSString *expected = @"a\\ \\(\\ \\ \\ \\ \r\r“”‘’–—b";
+    XCTAssert([_writeBuffer isEqualToString:expected]);
+}
+
+- (void)testDoNotEscapeNonAscii {
+    [_helper pasteString:@"“"
+                  slowly:NO
+        escapeShellChars:YES
+                commands:NO
+            tabTransform:kTabTransformEscapeWithCtrlV
+            spacesPerTab:0];
+    [self runTimer];
+    NSString *expected = @"“";
+    XCTAssert([_writeBuffer isEqualToString:expected]);
+}
+
+- (void)testStripControlV {
+    [_helper pasteString:@"\x16"
+                  slowly:NO
+        escapeShellChars:YES
+                commands:NO
+            tabTransform:kTabTransformEscapeWithCtrlV
+            spacesPerTab:0];
+    [self runTimer];
+    NSString *expected = @"";
     XCTAssert([_writeBuffer isEqualToString:expected]);
 }

sources/NSStringITerm.h

@@ -67,6 +67,7 @@ int decode_utf8_char(const unsigned char * restrict datap,
 // Returns the number of lines in a string.
 - (NSUInteger)numberOfLines;
 - (NSString *)stringWithEscapedShellCharactersIncludingNewlines:(BOOL)includingNewlines;
+- (NSString *)stringWithEscapedShellCharactersExceptTabAndNewline;
 // Replaces tab with ^V + tab.
 - (NSString *)stringWithShellEscapedTabs;

sources/NSStringITerm.m

@@ -110,6 +110,12 @@
     return [NSString stringWithString:aMutableString];
 }
+- (NSString *)stringWithEscapedShellCharactersExceptTabAndNewline {
+    NSMutableString *aMutableString = [[[NSMutableString alloc] initWithString:self] autorelease];
+    [aMutableString escapeShellCharactersExceptTabAndNewline];
+    return [NSString stringWithString:aMutableString];
+}
+
 - (NSString *)stringWithShellEscapedTabs
 {
     const int kLNEXT = 22;
@@ -1589,11 +1595,20 @@ static TECObjectRef CreateTECConverterForUTF8Variants(TextEncodingVariant varian
     }
 }
+- (void)escapeShellCharactersExceptTabAndNewline {
+    NSString *charsToEscape = [[NSString shellEscapableCharacters] stringByReplacingOccurrencesOfString:@"\t" withString:@""];
+    return [self escapeCharacters:charsToEscape];
+}
+
 - (void)escapeShellCharactersIncludingNewlines:(BOOL)includingNewlines {
     NSString* charsToEscape = [NSString shellEscapableCharacters];
     if (includingNewlines) {
         charsToEscape = [charsToEscape stringByAppendingString:@"\r\n"];
     }
+    [self escapeCharacters:charsToEscape];
+}
+
+- (void)escapeCharacters:(NSString *)charsToEscape {
     for (int i = 0; i < [charsToEscape length]; i++) {
         NSString* before = [charsToEscape substringWithRange:NSMakeRange(i, 1)];
         NSString* after = [@"\\" stringByAppendingString:before];

sources/iTermPasteHelper.m

@@ -127,17 +127,13 @@ const int kNumberOfSpacesPerTabNoConversion = -1;
                                                               range:NSMakeRange(0, theString.length)];
     }
-    if (flags & kPasteFlagsEscapeSpecialCharacters) {
-        // Put backslash before anything the shell might interpret.
-        theString = [theString stringWithEscapedShellCharactersIncludingNewlines:NO];
-    }
-
     if (flags & kPasteFlagsRemovingUnsafeControlCodes) {
-        // All control codes except tab (9), newline (10), form feed (12), and carriage return (13)
-        // are removed.
+        // All control codes except tab (9), newline (10), form feed (12), carriage return (13),
+        // and shell escape (22) are removed. This must be done before transforming tabs since
+        // that transformation might add ^Vs.
         theString =
-            [[theString componentsSeparatedByCharactersInSet:[iTermPasteHelper unsafeControlCodeSet]]
-                componentsJoinedByString:@""];
+        [[theString componentsSeparatedByCharactersInSet:[iTermPasteHelper unsafeControlCodeSet]]
+         componentsJoinedByString:@""];
     }
     switch (pasteEvent.tabTransform) {
@@ -156,6 +152,16 @@ const int kNumberOfSpacesPerTabNoConversion = -1;
             break;
     }
+    if (flags & kPasteFlagsEscapeSpecialCharacters) {
+        // Put backslash before anything the shell might interpret.
+        if (pasteEvent.tabTransform != kTabTransformEscapeWithCtrlV) {
+            theString = [theString stringWithEscapedShellCharactersIncludingNewlines:NO];
+        } else {
+            // Avoid double-escaping tabs with both ^V and backslash.
+            theString = [theString stringWithEscapedShellCharactersExceptTabAndNewline];
+        }
+    }
+
     if (pasteEvent.flags & kPasteFlagsUseRegexSubstitution && pasteEvent.regex.length > 0) {
         NSString *replacement = nil;
         @try {