Trim trailing slashes from the initial working directory, unless it is "/".

Fix a bug in stringByTrimmingTrailingCharactersFromCharacterSet:, where it should have removed everything when all the characters in the string belonged to the set.

Issue 5950

iTerm2XCTests/iTermNSStringCategoryTest.m

@@ -153,6 +153,14 @@
     [self assertString:@"\\~" parsesAsShellCommandTo:@[ @"~" ]];
 }
+- (void)testStringByTrimmingCharset {
+    XCTAssertEqualObjects([@"abc" stringByTrimmingTrailingCharactersFromCharacterSet:[NSCharacterSet characterSetWithCharactersInString:@"a"]], @"abc");
+    XCTAssertEqualObjects([@"abc" stringByTrimmingTrailingCharactersFromCharacterSet:[NSCharacterSet characterSetWithCharactersInString:@"c"]], @"ab");
+    XCTAssertEqualObjects([@"abc" stringByTrimmingTrailingCharactersFromCharacterSet:[NSCharacterSet characterSetWithCharactersInString:@"x"]], @"abc");
+    XCTAssertEqualObjects([@"abc" stringByTrimmingTrailingCharactersFromCharacterSet:[NSCharacterSet characterSetWithCharactersInString:@"bc"]], @"a");
+    XCTAssertEqualObjects([@"abc" stringByTrimmingTrailingCharactersFromCharacterSet:[NSCharacterSet characterSetWithCharactersInString:@"abc"]], @"");
+}
+
 - (void)testStringByTrimmingTrailingWhitespace {
     XCTAssert([[@"abc" stringByTrimmingTrailingWhitespace] isEqualToString:@"abc"]);
     XCTAssert([[@"abc " stringByTrimmingTrailingWhitespace] isEqualToString:@"abc"]);

sources/NSStringITerm.m

@@ -559,7 +559,11 @@ int decode_utf8_char(const unsigned char *datap,
     NSRange rangeOfLastWantedCharacter = [self rangeOfCharacterFromSet:invertedCharset
                                                                options:NSBackwardsSearch];
     if (rangeOfLastWantedCharacter.location == NSNotFound) {
-        return self;
+        if ([self rangeOfCharacterFromSet:charset].location == NSNotFound) {
+            return self;
+        } else {
+            return @"";
+        }
     } else if (rangeOfLastWantedCharacter.location + rangeOfLastWantedCharacter.length < self.length) {
         NSUInteger i = rangeOfLastWantedCharacter.location + rangeOfLastWantedCharacter.length;
         return [self substringToIndex:i];

sources/PTYSession.m

@@ -1686,6 +1686,13 @@ ITERM_WEAKLY_REFERENCEABLE
         env[PWD_ENVNAME] = [PWD_ENVVALUE stringByExpandingTildeInPath];
     }
+    // Remove trailing slashes, unless the path is just "/"
+    NSString *trimmed = [env[PWD_ENVNAME] stringByTrimmingTrailingCharactersFromCharacterSet:[NSCharacterSet characterSetWithCharactersInString:@"/"]];
+    if (trimmed.length == 0) {
+        trimmed = @"/";
+    }
+    env[PWD_ENVNAME] = trimmed;
+
     NSString *itermId = [self sessionId];
     env[@"ITERM_SESSION_ID"] = itermId;
     env[@"TERM_PROGRAM_VERSION"] = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];