AntPathPatternMatcher hardcoded "/" separator in variables matching and comparator

[tafjwr]

Related: #26264

When AntPathMatcher is constructed with a path separator other than default character "/", the functionality of extraction of URI template variables doesn’t work properly. If the matcher is specified with a non-default character, and a part of URI variable template includes default separator as a variable name, the variable name key mapping leads to exceptions or unexpected results. This is because the regex for URI template variables is hard-coded with "/", which is not considered as a part of variable key, although it can be placed if the matcher has a non-default path separator. To fix this, I updated it to pass a path separator to that regex.

Currently, for example, the matcher with non-default path separator seems to be leveraged on WebSocketConfiguration, in default, to map a "."-separated resource, which is a part of URI segment. Thus, for instance, if the path separator is specified as ".", extracting “price.stock.aaa“ with the template "price.stock.{ticker/symbol}" leads to IllegalStateException.

NOTE: A hard-coded variable pattern is still remaining. It seemed to be indirectly used in PathMatcher#compare implementation, but I’m not sure if this erroneous code causes some bug behaviors or not and is tracked by the team. And for isolation reasons, I would like to exclude it from the scope of code fix in this PR.

spring-framework/spring-core/src/main/java/org/springframework/util/AntPathMatcher.java

Line 81 in b134f25

private static final Pattern VARIABLE_PATTERN = Pattern.compile("\\{[^/]+?\\}");

[bclozel]

Thanks for your contribution @tafjwr , this is now in main and should be available in SNAPSHOTs soon.