Question

I frequently get what appears to be a stackoverflow error 😉 from YUICompressor. The following is the first part of thousands of error lines that come from attempting to compress a 24074 byte css stylesheet (not the “Caused by java.lang.StackOverflowError about 8 lines down):

iMac1:src jas$ min ../style2.min.css style2.css 
Exception in thread "main" java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.yahoo.platform.yui.compressor.Bootstrap.main(Bootstrap.java:21)
Caused by: java.lang.StackOverflowError
    at java.lang.Character.codePointAt(Character.java:2335)
    at java.util.regex.Pattern$CharProperty.match(Pattern.java:3344)
    at java.util.regex.Pattern$Branch.match(Pattern.java:4114)

… (plus 1021 more error lines)

The errors happen usually after adding a couple of lines to the file getting compressed. The css is fine, and works perfectly in the uncompressed format. I don’t see a particular pattern to the types of selectors added to the file that cause the errors. In this case, adding the following selector to a previously compressible file resulted in the errors:

#thisisatest
{
    margin-left:87px;
}

I am wondering if there is perhaps a flag to java to enlarge the stack that might help. Or if that is not the problem, what is?

EDIT:

As I was posting this question, it dawned on me that I should check the java command to see if there was a parameter to enlarge the stack. Turns out that it is -Xssn, where “n” is a parameter to indicate the stack size. Its default value is 512k. So I tried 1024k but that still led to the stackoverflow. Trying 2048k works however, and I think this could be the solution.

EDIT 2:

While I no longer use this method for minification any longer, to be more specific here is the full command (which I have set up as a shell alias), showing how the -Xss2048k parameter is used:

java -Xss2048k -jar ~/Documents/RepHunter/Website\ Materials/Code/Third\ Party\ Libraries/YUI\ Compressor/yuicompressor-2.4.8.jar –type css -o

Answer 1

As posted in my edit, the solution was to add the parameters to the java command. The clue was the error line at the 5-th “at” line, as follows:

at com.yahoo.platform.yui.compressor.Bootstrap.main(Bootstrap.java:21)
Caused by: java.lang.StackOverflowError

Seeing that the issue was a “StackOverlowError” 😉 gave the suggestion to try to increase the stack size. The default is 512k. My first try of 1024k did not work. However increasing it to 2048k did work, and I have had no further issues.