Fix loss of changes when multiple target the same start point

While one might at first think that multiple changes should conflict if they
target that same start point, that is not necessarily true as long as no more
than one of them includes deletions: There may be an arbitrary number of
insertions at the same position (regular remapping never just inserts but
patterns can).

1 files changed, 8 insertions, 2 deletions

diff --git a/src/main/kotlin/com/replaymod/gradle/remap/PsiMapper.kt b/src/main/kotlin/com/replaymod/gradle/remap/PsiMapper.kt
index a8d9f2a..c620c4c 100644
--- a/src/main/kotlin/com/replaymod/gradle/remap/PsiMapper.kt
+++ b/src/main/kotlin/com/replaymod/gradle/remap/PsiMapper.kt
@@ -31,7 +31,7 @@ internal class PsiMapper(
 ) {
     private val mixinMappings = mutableMapOf<String, ClassMapping<*, *>>()
     private val errors = mutableListOf<Pair<Int, String>>()
-    private val changes = TreeMap<TextRange, String>(Comparator.comparing<TextRange, Int> { it.startOffset })
+    private val changes = TreeMap<TextRange, String>(compareBy<TextRange> { it.startOffset }.thenBy { it.endOffset })
 
     private fun error(at: PsiElement, message: String) {
         val line = StringUtil.offsetToLineNumber(file.text, at.textOffset)
@@ -40,7 +40,13 @@ internal class PsiMapper(
 
     private fun replace(e: PsiElement, with: String) = replace(e.textRange, with)
     private fun replace(textRange: TextRange, with: String) {
-        changes[textRange] = with
+        changes.compute(textRange) { _, replacement ->
+            if (replacement != null) {
+                replacement + with
+            } else {
+                with
+            }
+        }
     }
 
     private fun replaceIdentifier(parent: PsiElement, with: String) {