Do not generate empty dex in multidex.

This was possible when the first class considered for adding in a dex was too
big to be sure it will fit. Now DX will try to add the class in the current dex
and crash if the class causes one index to overflow.

(cherry picked from commit f15dafe674d2270cafaf4fb7993963ec474d3761)

Change-Id: I323f8111c2be6bace908d0539ff324c4bd033c05

2 files changed, 5 insertions, 2 deletions

diff --git a/dx/src/com/android/dx/command/dexer/Main.java b/dx/src/com/android/dx/command/dexer/Main.java
index 406e2673b..c5f9c94f6 100644
--- a/dx/src/com/android/dx/command/dexer/Main.java
+++ b/dx/src/com/android/dx/command/dexer/Main.java
@@ -712,7 +712,10 @@ public class Main {
         int maxFieldIdsInDex = numFieldIds + constantPoolSize + cf.getFields().size() +
                 MAX_FIELD_ADDED_DURING_DEX_CREATION;
 
-        if (args.multiDex && ((maxMethodIdsInDex > args.maxNumberOfIdxPerDex) ||
+        if (args.multiDex
+            // Never switch to the next dex if current dex is already empty
+            && (outputDex.getClassDefs().items().size() > 0)
+            && ((maxMethodIdsInDex > args.maxNumberOfIdxPerDex) ||
                 (maxFieldIdsInDex > args.maxNumberOfIdxPerDex))) {
             DexFile completeDex = outputDex;
             createDexFile();
diff --git a/dx/src/com/android/dx/dex/file/DexFile.java b/dx/src/com/android/dx/dex/file/DexFile.java
index 01a5e4b50..103985ce5 100644
--- a/dx/src/com/android/dx/dex/file/DexFile.java
+++ b/dx/src/com/android/dx/dex/file/DexFile.java
@@ -323,7 +323,7 @@ public final class DexFile {
      *
      * @return {@code non-null;} the class definitions section
      */
-    /*package*/ ClassDefsSection getClassDefs() {
+    public ClassDefsSection getClassDefs() {
         return classDefs;
     }