decompiler: better line matching for single block methods

src/org/jetbrains/java/decompiler/main/collectors/BytecodeMappingTracer.java

@@ -101,6 +101,8 @@ public class BytecodeMappingTracer {
     }
 
     Map<Integer, Integer> res = new HashMap<Integer, Integer>();
+
+    // first match offsets from line number table
     int[] data = lineNumberTable.getRawData();
     for (int i = 0; i < data.length; i += 2) {
       int originalOffset = data[i];
@@ -113,9 +115,11 @@ public class BytecodeMappingTracer {
         unmappedLines.add(originalLine);
       }
     }
+
+    // now match offsets from decompiler mapping
     for (Entry<Integer, Integer> entry : mapping.entrySet()) {
       int originalLine = lineNumberTable.findLineNumber(entry.getKey());
-      if (originalLine > -1) {
+      if (originalLine > -1 && !res.containsKey(originalLine)) {
         res.put(originalLine, entry.getValue());
         unmappedLines.remove(originalLine);
       }

testData/results/InvalidMethodSignature.dec

@@ -12,9 +12,9 @@ class i implements bg {
    private final b b;
 
    i(b var1, j var2) {
-      this.b = var1;
+      this.b = var1;// 1
       this.a = var2;
-   }// 1
+   }
 
    public void a(c var1, k var2, boolean var3) {
       File var4 = this.a.b().a(var1);// 2
@@ -50,7 +50,7 @@ class 'a/a/a/a/e/f/i' {
 
 Lines mapping:
 0 <-> 25
-1 <-> 17
+1 <-> 15
 2 <-> 20
 3 <-> 21
 4 <-> 22

testData/results/TestEnum.dec

@@ -18,12 +18,12 @@ public enum TestEnum {
    }// 30
 
    private TestEnum() {
-      this("?");
+      this("?");// 34
-   }// 34
+   }
 
    private TestEnum(@Deprecated String var3) {
-      this.s = var3;
+      this.s = var3;// 35
-   }// 35
+   }
 }
 
 class 'pkg/TestEnum$1' {
@@ -59,5 +59,5 @@ Lines mapping:
 22 <-> 7
 27 <-> 12
 30 <-> 18
-34 <-> 22
+34 <-> 21
-35 <-> 26
+35 <-> 25