Error executing command ReviewCode: java.util.regex.PatternSyntaxException: Illegal/unsupported escape sequence near index

[hbrands]

Environment:
Windows 10
Spring Tool Suite
Version: 4.11.0.RELEASE
Build Id: 202106180608
(based on Eclipse 2021-06)

PMD Plug-in 4.24.0.v20210529-0600

I noticed a lot of errors in the PMD logfile:

2021/07/01 10:45:22.814 [Worker-173: ReviewCode] ERROR n.s.p.e.r.cmd.JobCommandProcessor - Error executing command ReviewCode: java.util.regex.PatternSyntaxException: Illegal/unsupported escape sequence near index 50
D:\workspace\sts490\edrewemaster\example-demo\src\main\java\**\*.java\.*
                                                  ^
java.util.regex.PatternSyntaxException: Illegal/unsupported escape sequence near index 50
D:\workspace\sts490\edrewemaster\example-demo\src\main\java\**\*.java\.*
                                                  ^
	at java.base/java.util.regex.Pattern.error(Pattern.java:2028)
	at java.base/java.util.regex.Pattern.escape(Pattern.java:2619)
	at java.base/java.util.regex.Pattern.atom(Pattern.java:2286)
	at java.base/java.util.regex.Pattern.sequence(Pattern.java:2210)
	at java.base/java.util.regex.Pattern.expr(Pattern.java:2069)
	at java.base/java.util.regex.Pattern.compile(Pattern.java:1783)
	at java.base/java.util.regex.Pattern.<init>(Pattern.java:1430)
	at java.base/java.util.regex.Pattern.compile(Pattern.java:1069)
	at net.sourceforge.pmd.eclipse.ui.actions.internal.InternalRuleSetUtil.convertStringPatterns(InternalRuleSetUtil.java:86)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.filteredRuleSets(ReviewCodeCmd.java:675)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.rulesetsFrom(ReviewCodeCmd.java:509)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.determineFileExtensions(ReviewCodeCmd.java:304)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.determineTotalWork(ReviewCodeCmd.java:274)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.execute(ReviewCodeCmd.java:181)
	at net.sourceforge.pmd.eclipse.runtime.cmd.JobCommandProcessor$1.run(JobCommandProcessor.java:60)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

The index 50 is around "\m" of \main in this example.
I will attach a sample project which demonstrates this problem.
Hopefully you can reproduce the issue.
example-demo.zip

[hbrands]

Maybe it's related to a change of commit
32840c9

[hbrands]

@adangel After updating to version 4.26.0 I still observe similiar exceptions in the log file. This time it complains about the project root dir:

2021/08/05 14:27:09.070 [Worker-3: ReviewCode] ERROR n.s.p.e.r.cmd.JobCommandProcessor - Error executing command ReviewCode: java.util.regex.PatternSyntaxException: Illegal/unsupported escape sequence near index 13
D:\workspace\gitlab\edrewemaster\edrewe-common\src\main\java\.*\*\.java
             ^
java.util.regex.PatternSyntaxException: Illegal/unsupported escape sequence near index 13
D:\workspace\gitlab\edrewemaster\edrewe-common\src\main\java\.*\*\.java
             ^
	at java.base/java.util.regex.Pattern.error(Pattern.java:2028)
	at java.base/java.util.regex.Pattern.escape(Pattern.java:2619)
	at java.base/java.util.regex.Pattern.atom(Pattern.java:2286)
	at java.base/java.util.regex.Pattern.sequence(Pattern.java:2210)
	at java.base/java.util.regex.Pattern.expr(Pattern.java:2069)
	at java.base/java.util.regex.Pattern.compile(Pattern.java:1783)
	at java.base/java.util.regex.Pattern.<init>(Pattern.java:1430)
	at java.base/java.util.regex.Pattern.compile(Pattern.java:1069)
	at net.sourceforge.pmd.eclipse.ui.actions.internal.InternalRuleSetUtil.convertStringPatterns(InternalRuleSetUtil.java:88)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.filteredRuleSets(ReviewCodeCmd.java:674)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.rulesetsFrom(ReviewCodeCmd.java:510)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.determineFileExtensions(ReviewCodeCmd.java:305)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.determineTotalWork(ReviewCodeCmd.java:275)
	at net.sourceforge.pmd.eclipse.runtime.cmd.ReviewCodeCmd.execute(ReviewCodeCmd.java:181)
	at net.sourceforge.pmd.eclipse.runtime.cmd.JobCommandProcessor$1.run(JobCommandProcessor.java:60)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

This is with my real projects. I couldn't reproduce this with a test project yet. When I have more insights I'll let you know.

[hbrands]

@adangel UPDATE: I think you can reproduce the remaining issue with my provided example project above if you extract it on Windows in a dir like "D:\workspace\gitlab" and import it as an existing project into an Eclipse workspace. It seems to me that the backsplash in the root path is not escaped for the regex, so "\g" is not recognized by Pattern#compile (whereas "\w" and "\e" is interpreted by Pattern#compile). Hope this helps.

[hbrands]

@adangel Unfortunately I can't reopen the issue. Should I create a new issue?
Please give a short feedback, so that I know you have noticed my comments and I know what I should do.

[adangel]

@hbrands Please create a new issue, thanks.