Bug 51093 [typing] Pressing enter after an opening curly brace closes the curly brace repeatedly.
Pressing enter after an opening curly brace closes the curly brace repeatedly. IF you are about to define a method and you open a curly brace, the completion closing curly brace is added automatically. If you go and press "enter" again in front of the opening curly brace , it adds another closing brace repeatedly.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/JavaAutoIndentStrategy.java
* Returns the visual length of a given <code>CharSequence</code> taking into
	 * account the visual tabulator length.
	 * 
	 * @param seq the string to measure
	 * @return the visual length of <code>seq</code>
	 */
	private static int computeVisualLength(CharSequence seq) {
		int size= 0;
		int tablen= getVisualTabLengthPreference();
		
		for (int i= 0; i < seq.length(); i++) {
			char ch= seq.charAt(i);
			if (ch == '\t')
				size += tablen - size % tablen;
			else
				size++;
		}
		return size;
	}
	
	/**
	 * Returns the visual length of a given character taking into
	 * account the visual tabulator length.
	 * 
	 * @param ch the character to measure
	 * @return the visual length of <code>ch</code>
	 */
	private static int computeVisualLength(char ch) {
		if (ch == '\t')
			return getVisualTabLengthPreference();