Merge branch 'QuentinC-fix-tab-escape' into master

The contribution branch was rebased to current master.
This should close #1065 as merged.

Author: flaix

src/main/java/com/gitblit/utils/StringUtils.java

@@ -105,6 +105,8 @@ public static String escapeForHtml(String inStr, boolean changeSpace) {
 	public static String escapeForHtml(String inStr, boolean changeSpace, int tabLength) {
 		StringBuilder retStr = new StringBuilder();
 		int i = 0;
+		int l = 0;
+		
 		while (i < inStr.length()) {
 			if (inStr.charAt(i) == '&') {
 				retStr.append("&amp;");
@@ -117,12 +119,18 @@ public static String escapeForHtml(String inStr, boolean changeSpace, int tabLen
 			} else if (changeSpace && inStr.charAt(i) == ' ') {
 				retStr.append("&nbsp;");
 			} else if (changeSpace && inStr.charAt(i) == '\t') {
-				for (int j = 0; j < tabLength; j++) {
+				for (int j = 0; j < tabLength - l; j++) {
 					retStr.append("&nbsp;");
 				}
+				l = -1;
 			} else {
 				retStr.append(inStr.charAt(i));
 			}
+			
+			l = (l + 1) % tabLength;
+			if (inStr.charAt(i) == '\n') {
+				l = 0;
+			}
 			i++;
 		}
 		return retStr.toString();

src/test/java/com/gitblit/tests/StringUtilsTest.java

@@ -61,11 +61,39 @@ public void testEncodeUrl() throws Exception {
 
 	@Test
 	public void testEscapeForHtml() throws Exception {
-		String input = "& < > \" \t";
-		String outputNoChange = "&amp; &lt; &gt; &quot; \t";
-		String outputChange = "&amp;&nbsp;&lt;&nbsp;&gt;&nbsp;&quot;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";
+		String input = "\t & < > \"";
+		String outputNoChange = "\t &amp; &lt; &gt; &quot;";
+		String outputChange = "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&amp;&nbsp;&lt;&nbsp;&gt;&nbsp;&quot;";
 		assertEquals(outputNoChange, StringUtils.escapeForHtml(input, false));
 		assertEquals(outputChange, StringUtils.escapeForHtml(input, true));
+
+		input = "a\tb";
+		outputNoChange = "a\tb";
+		outputChange = "a&nbsp;&nbsp;&nbsp;b";
+		assertEquals(outputNoChange, StringUtils.escapeForHtml(input, false));
+		assertEquals(outputChange, StringUtils.escapeForHtml(input, true));
+
+		input = "\ta b\t";
+		outputNoChange = "\ta b\t";
+		outputChange = "&nbsp;&nbsp;&nbsp;&nbsp;a&nbsp;b&nbsp;";
+		assertEquals(outputNoChange, StringUtils.escapeForHtml(input, false));
+		assertEquals(outputChange, StringUtils.escapeForHtml(input, true));
+
+		input = "\t <> \t";
+		outputNoChange = "\t &lt;&gt; \t";
+		outputChange = "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;&gt;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;";
+		assertEquals(outputNoChange, StringUtils.escapeForHtml(input, false));
+		assertEquals(outputChange, StringUtils.escapeForHtml(input, true));
+
+		String tabs = "\t";
+		int tabSpaces;
+		int expectedLength;
+		for (int i = 0; i < 50; i++) {
+			tabSpaces = 4 - i % 4;
+			expectedLength = (i + tabSpaces) * 6; // &nbsp; = 6 chars
+			assertEquals(expectedLength, StringUtils.escapeForHtml(tabs, true).length());
+			tabs = " " + tabs;
+		}
 	}
 
 	@Test