Loading a FileConfiguration (Yaml/) should remember the previously saved header

By: Nathan Adams <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/configuration/file/YamlConfiguration.java

@@ -61,6 +61,7 @@ public class YamlConfiguration extends FileConfiguration {
             throw new InvalidConfigurationException("Specified contents is not a valid Configuration", ex);
         }
         
+        options().header(parseHeader(contents));
         deserializeValues(input, this);
     }
     
@@ -129,6 +130,32 @@ public class YamlConfiguration extends FileConfiguration {
         }
     }
     
+    protected String parseHeader(String input) {
+        String[] lines = input.split("\r?\n", -1);
+        StringBuilder result = new StringBuilder();
+        boolean readingHeader = true;
+        
+        for (int i = 0; (i < lines.length) && (readingHeader); i++) {
+            String line = lines[i];
+            
+            if (line.startsWith(COMMENT_PREFIX)) {
+                if (i > 0) {
+                    result.append("\n");
+                }
+                
+                if (line.length() > COMMENT_PREFIX.length()) {
+                    result.append(line.substring(COMMENT_PREFIX.length()));
+                }
+            } else if (line.length() == 0) {
+                result.append("\n");
+            } else {
+                readingHeader = false;
+            }
+        }
+        
+        return result.toString();
+    }
+    
     protected String buildHeader() {
         String header = options().header();
         

paper-api/src/test/java/org/bukkit/configuration/file/YamlConfigurationTest.java

@@ -60,6 +60,25 @@ public  class YamlConfigurationTest extends FileConfigurationTest {
         assertEquals(expected, result);
     }
 
+    @Test
+    public void testParseHeader() throws Exception {
+        YamlConfiguration config = getConfig();
+        Map<String, Object> values = getTestValues();
+        String saved = getTestValuesString();
+        String header = "# This is a sample\n# header.\n# \n# Newline above should be commented.\n\n\n";
+        String expected = "This is a sample\nheader.\n\nNewline above should be commented.\n\n";
+        
+        config.loadFromString(header + saved);
+        
+        assertEquals(expected, config.options().header());
+        
+        for (Map.Entry<String, Object> entry : values.entrySet()) {
+            assertEquals(entry.getValue(), config.get(entry.getKey()));
+        }
+        
+        assertEquals(values.keySet(), config.getKeys(true));
+    }
+
     @Test
     public void testSaveToStringWithIndent() {
         YamlConfiguration config = getConfig();