CFScript bug?

An extra semicolon at the end of "if" block is causing a lot of head scratching for me recently. Please see the code snippet below.

	<cfscript>
	private struct function test() {
	if(1 == 1) {
	if(1 == 0) {
	writeOutput("1==0");
	};
	writeOutput("true");
	return {data = 1};
	}
	writeOutput("false");
	return {data = 2};
	}
	writeDump(test());
	</cfscript>

view raw CFScript Problem hosted with ❤ by GitHub

Expected output should be:

Figure 1. Expected Output

However, below is the actual output:

Figure 2. Actual Output

Now, please notice this extra ";" at the end of line 6. If I remove it, everything will just work as expected.

<cfscript>
    private struct function test() {
        if(1 == 1) {
            if(1 == 0) {
                writeOutput("1==0");
            }; //<- look at here
            writeOutput("true");
            return {data = 1};
        }
        writeOutput("false");
        return {data = 2};
    }
    writeDump(test());
</cfscript>

Due to the lack of specifications for CFScript language, I cannot tell if this grammar is even allowed. But I can tell you this: the journey of discovering and finding the root cause of this problem is not fun at all!

Symptom

CFScript fall through the "if-else" statement, and did not return to caller from the expected branch.

Cause

An extra semicolon at the end of a block is the root cause.