1 files changed, 7 insertions, 3 deletions

diff --git a/enigma/src/main/java/cuchaz/enigma/translation/mapping/serde/enigma/EnigmaMappingsReader.java b/enigma/src/main/java/cuchaz/enigma/translation/mapping/serde/enigma/EnigmaMappingsReader.java
index 04b4534b..61dbe93a 100644
--- a/enigma/src/main/java/cuchaz/enigma/translation/mapping/serde/enigma/EnigmaMappingsReader.java
+++ b/enigma/src/main/java/cuchaz/enigma/translation/mapping/serde/enigma/EnigmaMappingsReader.java
@@ -104,7 +104,7 @@ public enum EnigmaMappingsReader implements MappingsReader {
 
                 for (int lineNumber = 0; lineNumber < lines.size(); lineNumber++) {
                         String line = lines.get(lineNumber);
-                        int indentation = countIndentation(line);
+                        int indentation = countIndentation(line, path, lineNumber);
 
                         line = formatLine(line);
                         if (line == null) {
@@ -120,7 +120,7 @@ public enum EnigmaMappingsReader implements MappingsReader {
                                 }
                         } catch (Throwable t) {
                                 t.printStackTrace();
-                                throw new MappingParseException(path::toString, lineNumber, t.toString());
+                                throw new MappingParseException(path::toString, lineNumber + 1, t.toString());
                         }
                 }
 
@@ -162,9 +162,13 @@ public enum EnigmaMappingsReader implements MappingsReader {
                 return line;
         }
 
-        private static int countIndentation(String line) {
+        private static int countIndentation(String line, Path path, int lineNumber) throws MappingParseException {
                 int indent = 0;
                 for (int i = 0; i < line.length(); i++) {
+                        if (line.charAt(i) == ' ') {
+                                throw new MappingParseException(path::toString, lineNumber + 1, "Spaces must not be used to indent lines!");
+                        }
+
                         if (line.charAt(i) != '\t') {
                                 break;
                         }