<style>
/* Changing the layout to use less space for mobiles */
@media screen and (max-device-width: 480px), screen and (-webkit-min-device-pixel-ratio: 2) {
#email-body { min-width: 30em !important; }
#email-page { padding: 8px !important; }
#email-banner { padding: 8px 8px 0 8px !important; }
#email-avatar { margin: 1px 8px 8px 0 !important; padding: 0 !important; }
#email-fields { padding: 0 8px 8px 8px !important; }
#email-gutter { width: 0 !important; }
}
</style>
<div id="email-body">
<table id="email-wrap" align="center" border="0" cellpadding="0" cellspacing="0" style="background-color:#f0f0f0;color:#000000;width:100%;">
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<td id="email-page" style="padding:16px !important;">
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<table align="left" border="0" cellpadding="0" cellspacing="0" width="100%" style="width:100%;">
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<img id="email-avatar" src="http://jira.qos.ch/secure/useravatar?avatarId=10122" alt="" height="48" width="48" border="0" align="left" style="padding:0;margin: 0 16px 16px 0;" />
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<a class="user-hover" rel="nmccloud" id="email_nmccloud" href="http://jira.qos.ch/secure/ViewProfile.jspa?name=nmccloud" style="color:#326ca6;">Kenneth Gendron</a>
commented on <img src="http://jira.qos.ch/images/icons/issuetypes/bug.png" height="16" width="16" border="0" align="absmiddle" alt="Bug"> <a style='color:#326ca6;text-decoration:none;' href='http://jira.qos.ch/browse/LOGBACK-1027'>LOGBACK-1027</a>
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<a style='color:#326ca6;text-decoration:none;' href='http://jira.qos.ch/browse/LOGBACK-1027'><strong>Circular Referenced Suppressed Exception Throws StackOverflowError</strong></a>
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<td id="email-fields" style="padding:0 32px 32px 32px;">
<table border="0" cellpadding="0" cellspacing="0" style="padding:0;text-align:left;width:100%;" width="100%">
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<td id="email-gutter" style="width:64px;white-space:nowrap;"></td>
<td>
<table border="0" cellpadding="0" cellspacing="0" width="100%">
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<td colspan="2" style="color:#000000;font-family:Arial,FreeSans,Helvetica,sans-serif;font-size:12px;padding:0 0 16px 0;width:100%;">
<div class="comment-block" style="background-color:#edf5ff;border:1px solid #dddddd;color:#000000;padding:12px;"><p>I found a possible solution. Within ch.qos.logback.classic.spi.ThrowableProxy, replace the default constructor with the following field, constructors and method:</p>
<div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent">
<pre class="code-java"> <span class="code-keyword">private</span> <span class="code-keyword">static</span> <span class="code-keyword">final</span> StackTraceElementProxy[] NO_STACK_TRACE=<span class="code-keyword">new</span> StackTraceElementProxy[0];
<span class="code-keyword">public</span> ThrowableProxy(Throwable throwable) {
<span class="code-keyword">this</span>(throwable, <span class="code-keyword">null</span>, <span class="code-keyword">false</span>);
}
<span class="code-keyword">public</span> ThrowableProxy(Throwable throwable, Set<Throwable> exclude, <span class="code-object">boolean</span> circular) {
<span class="code-keyword">this</span>.throwable = throwable;
<span class="code-keyword">if</span> (!circular) {
<span class="code-keyword">this</span>.className = throwable.getClass().getName();
<span class="code-keyword">this</span>.message = throwable.getMessage();
<span class="code-keyword">this</span>.stackTraceElementProxyArray = ThrowableProxyUtil.steArrayToStepArray(throwable
.getStackTrace());
Throwable nested = throwable.getCause();
<span class="code-keyword">if</span> (nested != <span class="code-keyword">null</span>) {
<span class="code-keyword">if</span> (exclude==<span class="code-keyword">null</span>) {
exclude = createExcludeSet(throwable);
}
<span class="code-keyword">if</span> (!exclude.contains(nested)) {
exclude.add(nested);
<span class="code-keyword">this</span>.cause = <span class="code-keyword">new</span> ThrowableProxy(nested, exclude, <span class="code-keyword">false</span>);
<span class="code-keyword">this</span>.cause.commonFrames = ThrowableProxyUtil
.findNumberOfCommonFrames(nested.getStackTrace(),
stackTraceElementProxyArray);
} <span class="code-keyword">else</span> {
<span class="code-keyword">this</span>.cause = <span class="code-keyword">new</span> ThrowableProxy(nested, exclude, <span class="code-keyword">true</span>);
}
}
<span class="code-keyword">if</span>(GET_SUPPRESSED_METHOD != <span class="code-keyword">null</span>) {
<span class="code-comment">// <span class="code-keyword">this</span> will only execute on Java 7
</span> <span class="code-keyword">try</span> {
<span class="code-object">Object</span> obj = GET_SUPPRESSED_METHOD.invoke(throwable);
<span class="code-keyword">if</span>(obj <span class="code-keyword">instanceof</span> Throwable[]) {
Throwable[] throwableSuppressed = (Throwable[]) obj;
<span class="code-keyword">if</span>(throwableSuppressed.length > 0) {
suppressed = <span class="code-keyword">new</span> ThrowableProxy[throwableSuppressed.length];
<span class="code-keyword">if</span> (exclude==<span class="code-keyword">null</span>) {
exclude = createExcludeSet(throwable);
}
<span class="code-keyword">for</span>(<span class="code-object">int</span> i=0;i<throwableSuppressed.length;i++) {
<span class="code-keyword">if</span> (!exclude.contains(throwableSuppressed[i])) {
exclude.add(throwableSuppressed[i]);
<span class="code-keyword">this</span>.suppressed[i] = <span class="code-keyword">new</span> ThrowableProxy(throwableSuppressed[i], exclude, <span class="code-keyword">false</span>);
<span class="code-keyword">this</span>.suppressed[i].commonFrames = ThrowableProxyUtil
.findNumberOfCommonFrames(throwableSuppressed[i].getStackTrace(),
stackTraceElementProxyArray);
} <span class="code-keyword">else</span> {
<span class="code-keyword">this</span>.suppressed[i] = <span class="code-keyword">new</span> ThrowableProxy(throwableSuppressed[i], exclude, <span class="code-keyword">true</span>);
}
}
}
}
} <span class="code-keyword">catch</span> (IllegalAccessException e) {
<span class="code-comment">// ignore
</span> } <span class="code-keyword">catch</span> (InvocationTargetException e) {
<span class="code-comment">// ignore
</span> }
}
} <span class="code-keyword">else</span> {
<span class="code-keyword">this</span>.className = <span class="code-quote">"[CIRCULAR REFERENCE:"</span> + throwable.getClass().getName();
<span class="code-keyword">this</span>.message = throwable.getMessage() + <span class="code-quote">"]"</span>;
<span class="code-keyword">this</span>.stackTraceElementProxyArray = NO_STACK_TRACE;
}
}
<span class="code-keyword">private</span> <span class="code-keyword">static</span> Set<Throwable> createExcludeSet(Throwable parent) {
Set<Throwable> exclude = Collections.newSetFromMap(<span class="code-keyword">new</span> IdentityHashMap<Throwable, <span class="code-object">Boolean</span>>());
exclude.add(parent);
<span class="code-keyword">return</span> exclude;
}
</pre>
</div></div>
<p>Basically, it will use an IdentityHashMap to maintain the throwable proxies created, partially skipping those that have already been processed.</p>
<p>To minimize the string concatenation, the message could just be shortened to throwable.getMessage(), although something must be prepended to the class name to indicate its a circular reference.</p>
<p>The above code would then generate:</p>
<div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent">
<pre class="code-java">ERROR ROOT - Error
java.lang.Exception: <span class="code-keyword">null</span>
at NewClass.main(NewClass.java:20) ~[classes/:na]
Suppressed: java.lang.Exception: <span class="code-keyword">null</span>
at NewClass.main(NewClass.java:21) ~[classes/:na]
Suppressed: [CIRCULAR REFERENCE:java.lang.Exception: <span class="code-keyword">null</span>]
</pre>
</div></div></div>
<div style="color:#505050;padding:4px 0 0 0;"> </div>
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</td><!-- End #email-page -->
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