From b64bde56638938ce147ed26d8ed07ab02422f84a Mon Sep 17 00:00:00 2001
From: Som Snytt <som.snytt@gmail.com>
Date: Thu, 31 Aug 2023 02:24:50 -0700
Subject: [PATCH] Tweak java getlitch not to skip zero

[Cherry-picked 5f29c2178fc253a0fcfd8af0100e18ff434ea546]
---
 .../src/dotty/tools/dotc/parsing/JavaScanners.scala  |  6 ++++--
 tests/run/t12290.check                               |  8 ++++++++
 tests/run/t12290/Test.scala                          | 12 ++++++++++++
 tests/run/t12290/TextBlocks.java                     |  3 +++
 4 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/compiler/src/dotty/tools/dotc/parsing/JavaScanners.scala b/compiler/src/dotty/tools/dotc/parsing/JavaScanners.scala
index d21d4b85b5df..6a1d5d8b216c 100644
--- a/compiler/src/dotty/tools/dotc/parsing/JavaScanners.scala
+++ b/compiler/src/dotty/tools/dotc/parsing/JavaScanners.scala
@@ -439,6 +439,7 @@ object JavaScanners {
         }
         oct.asInstanceOf[Char]
       end octal
+      var skip = false
       def greatEscape: Char =
         nextChar()
         if '0' <= ch && ch <= '7' then octal
@@ -455,11 +456,12 @@ object JavaScanners {
             case '\\' => '\\'
             case CR | LF if inTextBlock =>
               if !scanOnly then nextChar()
+              skip = true
               0
             case _    =>
               if !scanOnly then error("invalid escape character", charOffset - 1)
               ch
-          if x != 0 then nextChar()
+          if !skip then nextChar()
           x
       end greatEscape
 
@@ -470,7 +472,7 @@ object JavaScanners {
           val res = ch
           nextChar()
           res
-      if c != 0 && !scanOnly then putChar(c)
+      if !skip && !scanOnly then putChar(c)
     end getlitch
 
     /** Read a triple-quote delimited text block, starting after the first three double quotes.
diff --git a/tests/run/t12290.check b/tests/run/t12290.check
index c6ce23a28ef2..f5367692b5f8 100644
--- a/tests/run/t12290.check
+++ b/tests/run/t12290.check
@@ -64,3 +64,11 @@ XY
 ====
 X Y
 ====
+582059
+====
+00
+====
+2a
+====
+c3bf
+====
diff --git a/tests/run/t12290/Test.scala b/tests/run/t12290/Test.scala
index e6c96573f032..7b0133e61c1f 100644
--- a/tests/run/t12290/Test.scala
+++ b/tests/run/t12290/Test.scala
@@ -30,4 +30,16 @@ object Test extends App {
   println("====")
   println(valueOf[TextBlocks.Octal.type])
   println("====")
+  println(hexdump(valueOf[TextBlocks.Octal.type]))
+  println("====")
+  println(hexdump(valueOf[TextBlocks.Zero.type].toString))
+  println("====")
+  println(hexdump(valueOf[TextBlocks.Magic.type].toString))
+  println("====")
+  println(hexdump(valueOf[TextBlocks.Maxie.type].toString))
+  println("====")
 }
+
+def hexdump(s: String) = s.getBytes(io.Codec.UTF8.charSet) // java.nio.charset.StandardCharsets.UTF_8
+                          .map(b => f"${b & 0xff}%02x")
+                          .mkString
diff --git a/tests/run/t12290/TextBlocks.java b/tests/run/t12290/TextBlocks.java
index 6a827923a052..9dd34e1546a5 100644
--- a/tests/run/t12290/TextBlocks.java
+++ b/tests/run/t12290/TextBlocks.java
@@ -81,4 +81,7 @@ class TextBlocks {
 """;
 
     final static String Octal = "X\040Y";
+    final static char Zero = '\0';
+    final static char Magic = '\52';
+    final static char Maxie = '\377';
 }