Incorrect guessing of script type when string constant contains XML tags

[gmbecker]

See:

options(error = function() traceback(2))
cat("shiny::HTML(\"or <code>CMD(/CTRL)+SHIFT+Enter</code>\")",
    file = "~/test.R")

library(CodeDepends)
script <- readScript("~/test.R")
-----------------------------------------------------------------------
Error: XML content does not seem to be XML: 'shiny::HTML("or <code>CMD(/CTRL)+SHIFT+Enter</code>")'
In addition: Warning message:
In readLines(doc) : incomplete final line found on '~/test.R'
7: (function () 
   traceback(2))()
6: (if (isHTML) warning else stop)(e)
5: xmlParse(txt, asText = TRUE)
4: readXMLScript(xmlParse(txt, asText = TRUE), ...)
3: frag.readers[[type]](doc, txt = txt, ...)
2: readScript("~/test.R")
1: readScript("~/test.R")

The above code works fine if type="R" is added to the readScript call.