escaped values on their own line cause erroneous compilation error

[coreywoodfield]

Somewhere between semanticdb version 4.7.8 and 4.8.15, the following bug was introduced. It is also reproducible in 4.9.1.

scala version: 2.13.12

Bug reproduction steps

Attempt to compile the following code with scalac Test.scala -Xplugin:semanticdb-plugin_singlejar.jar -Xsource:3

object Test {
  val `f-oo` = 1
  def bar =
    `f-oo`
}

Note that it fails with

Test.scala:3: error: illegal start of simple expression
  def bar =
           ^

If the newline is removed

object Test {
  val `f-oo` = 1
  def bar = `f-oo`
}

it compiles just fine. If -Xsource:3 or -Xplugin:semanticdb-plugin_singlejar.jar are left off, it compiles fine.

Expected behavior

The semanticdb plugin does not cause compiler errors when run with -Xsource:3 on code that compiles without the plugin

[kitbellew]

@coreywoodfield i don't think this repo defines the semanticdb plugin; therefore, please try to reproduce with scalameta directly and supply the dialect which shows this error.

[tgodzik]

We do publish semanticdb plugin and it uses the same version of scalameta. This looks like one of the issues already reported, no?

[kitbellew]

We do publish semanticdb plugin and it uses the same version of scalameta.

oh, didn't realize that.

This looks like one of the issues already reported, no?

possibly, need to test. backquoted id can be a leading infix, and in the form presented here was fixed in 4.9.1 (if what's reproducible in 4.9.1 is exactly this). if, however, it comes with a trailing blank line, it's the same issue as what #3606 fixed.