Fix: Issues with .properties format using whitespace delimited key (#2241)

Added:
- support for space delimitor in every case, included multiline value
- check for odd number of backslash escapes
- "!" as comment start
- support for escape of spaces and separators
Dropped:
- undocumented ";" and "//" comment start

2 files changed, 89 insertions, 37 deletions

diff --git a/tests/examplefiles/properties/java.properties b/tests/examplefiles/properties/java.properties
index 72ad0f96..d5b594e3 100644
--- a/tests/examplefiles/properties/java.properties
+++ b/tests/examplefiles/properties/java.properties
@@ -1,16 +1,24 @@
-foo = bar
-foo: bar
-foo.oof: \
-    bar=baz; \
-    asdf
+#https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Properties.htm
+# mixing spaces
+	Truth = Beauty
+  Truth:Beauty
+Truth	Beauty
+Truth                    :Beauty
+ 
+! line continuations and escapes
+ fruits                           apple, banana, pear, \
+                                  cantaloupe, watermelon, \
+                                  kiwi, mango
+key = \
+    value1 \\\
+    and value2\\
+key\ 2 = value
+key\\ 3 = value3
 
-// comment
-# comment
-; comment
-
-x:a\
-b
-x: a \
-  b
-
-x = \
+! empty keys and edge cases
+key1 =
+key2
+key3 the value3
+key4 the:value4
+key5 the=value5
+key6=the value6
diff --git a/tests/examplefiles/properties/java.properties.output b/tests/examplefiles/properties/java.properties.output
index 3efd7e2a..0c1fdeeb 100644
--- a/tests/examplefiles/properties/java.properties.output
+++ b/tests/examplefiles/properties/java.properties.output
@@ -1,50 +1,94 @@
-'foo'         Name.Attribute
+'#https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/util/Properties.htm' Comment.Single
+'\n'          Text.Whitespace
+
+'# mixing spaces' Comment.Single
+'\n\t'        Text.Whitespace
+'Truth'       Name.Attribute
 ' '           Text.Whitespace
 '='           Operator
 ' '           Text.Whitespace
-'bar'         Literal.String
+'Beauty'      Literal.String
+'\n  '        Text.Whitespace
+'Truth'       Name.Attribute
+':'           Operator
+'Beauty'      Literal.String
 '\n'          Text.Whitespace
 
-'foo'         Name.Attribute
-':'           Operator
-' '           Text.Whitespace
-'bar'         Literal.String
+'Truth'       Name.Attribute
+'\t'          Text.Whitespace
+'Beauty'      Literal.String
 '\n'          Text.Whitespace
 
-'foo.oof'     Name.Attribute
+'Truth'       Name.Attribute
+'                    ' Text.Whitespace
 ':'           Operator
-' '           Text.Whitespace
-'\\\n    bar=baz; \\\n    asdf' Literal.String
-'\n'          Text.Whitespace
+'Beauty'      Literal.String
+'\n \n'       Text.Whitespace
 
+'! line continuations and escapes' Comment.Single
+'\n '         Text.Whitespace
+'fruits'      Name.Attribute
+'                           ' Text.Whitespace
+'apple, banana, pear, ' Literal.String
+'\\'          Text
+'\n                                  ' Text.Whitespace
+'cantaloupe, watermelon, ' Literal.String
+'\\'          Text
+'\n                                  ' Text.Whitespace
+'kiwi, mango' Literal.String
 '\n'          Text.Whitespace
 
-'// comment'  Comment
+'key'         Name.Attribute
+' '           Text.Whitespace
+'='           Operator
+' '           Text.Whitespace
+'\\'          Text
+'\n    '      Text.Whitespace
+'value1 \\\\' Literal.String
+'\\'          Text
+'\n    '      Text.Whitespace
+'and value2\\\\' Literal.String
 '\n'          Text.Whitespace
 
-'# comment'   Comment
+'key\\ 2'     Name.Attribute
+' '           Text.Whitespace
+'='           Operator
+' '           Text.Whitespace
+'value'       Literal.String
 '\n'          Text.Whitespace
 
-'; comment'   Comment
+'key\\\\'     Name.Attribute
+' '           Text.Whitespace
+'3 = value3'  Literal.String
+'\n\n'        Text.Whitespace
+
+'! empty keys and edge cases' Comment.Single
 '\n'          Text.Whitespace
 
+'key1'        Name.Attribute
+' '           Text.Whitespace
+'='           Operator
 '\n'          Text.Whitespace
 
-'x'           Name.Attribute
-':'           Operator
-'a\\\nb'      Literal.String
+'key2'        Name.Attribute
 '\n'          Text.Whitespace
 
-'x'           Name.Attribute
-':'           Operator
+'key3'        Name.Attribute
 ' '           Text.Whitespace
-'a \\\n  b'   Literal.String
+'the value3'  Literal.String
 '\n'          Text.Whitespace
 
+'key4'        Name.Attribute
+' '           Text.Whitespace
+'the:value4'  Literal.String
 '\n'          Text.Whitespace
 
-'x'           Name.Attribute
+'key5'        Name.Attribute
 ' '           Text.Whitespace
+'the=value5'  Literal.String
+'\n'          Text.Whitespace
+
+'key6'        Name.Attribute
 '='           Operator
-' '           Text.Whitespace
-'\\\n'        Literal.String
+'the value6'  Literal.String
+'\n'          Text.Whitespace