Make <arg line="''"/> closer to what a shell would do.

PR: 5906

Don't use <arg line="..." />!


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273209 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -25,6 +25,10 @@ Fixed bugs:
 
 * <property>'s classpathref attribute was broken.
 
+* <arg line="''" /> would result in no command line argument, will now
+  be a single empty argument.  Use <arg value="''"/> if you need the
+  quotes literally.
+
 Other changes:
 --------------
 

docs/manual/using.html

@@ -431,10 +431,6 @@ that contain space characters, nested <code>arg</code> elements can be used.</p>
       characters.</td>
     <td align="center" rowspan="4">Exactly one of these.</td>
   </tr>
-  <tr>
-    <td valign="top">line</td>
-    <td valign="top">a space-delimited list of command-line arguments.</td>
-  </tr>
   <tr>
     <td valign="top">file</td>
     <td valign="top">The name of a file as a single command-line
@@ -448,7 +444,17 @@ that contain space characters, nested <code>arg</code> elements can be used.</p>
       path separators and Ant will convert it to the platform's local
       conventions.</td>
   </tr>
+  <tr>
+    <td valign="top">line</td>
+    <td valign="top">a space-delimited list of command-line arguments.</td>
+  </tr>
 </table>
+
+<p>It is highly recommended to avoid the <code>line</code> version
+when possible.  Ant will try to split the command line in a way
+similar to what a (Unix) shell would do, but may create something that
+is very different from what you expect under some circumstances.</p>
+
 <h4>Examples</h4>
 <blockquote><pre>
   &lt;arg value=&quot;-l -a&quot;/&gt;

src/main/org/apache/tools/ant/types/Commandline.java

@@ -356,12 +356,14 @@ public class Commandline implements Cloneable {
         StringTokenizer tok = new StringTokenizer(to_process, "\"\' ", true);
         Vector v = new Vector();
         StringBuffer current = new StringBuffer();
+        boolean lastTokenHasBeenQuoted = false;
 
         while (tok.hasMoreTokens()) {
             String nextTok = tok.nextToken();
             switch (state) {
             case inQuote:
                 if ("\'".equals(nextTok)) {
+                    lastTokenHasBeenQuoted = true;
                     state = normal;
                 } else {
                     current.append(nextTok);
@@ -369,6 +371,7 @@ public class Commandline implements Cloneable {
                 break;
             case inDoubleQuote:
                 if ("\"".equals(nextTok)) {
+                    lastTokenHasBeenQuoted = true;
                     state = normal;
                 } else {
                     current.append(nextTok);
@@ -380,18 +383,19 @@ public class Commandline implements Cloneable {
                 } else if ("\"".equals(nextTok)) {
                     state = inDoubleQuote;
                 } else if (" ".equals(nextTok)) {
-                    if (current.length() != 0) {
+                    if (lastTokenHasBeenQuoted || current.length() != 0) {
                         v.addElement(current.toString());
                         current.setLength(0);
                     }
                 } else {
                     current.append(nextTok);
                 }
+                lastTokenHasBeenQuoted = false;
                 break;
             }
         }
 
-        if (current.length() != 0) {
+        if (lastTokenHasBeenQuoted || current.length() != 0) {
             v.addElement(current.toString());
         }
 

src/testcases/org/apache/tools/ant/types/CommandlineTest.java

@@ -1,7 +1,7 @@
 /*
  * The Apache Software License, Version 1.1
  *
- * Copyright (c) 2000-2001 The Apache Software Foundation.  All rights
+ * Copyright (c) 2000-2002 The Apache Software Foundation.  All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -118,6 +118,31 @@ public class CommandlineTest extends TestCase {
         assertEquals("case with quoted whitespace", 4, s.length);
         assertEquals("backslash included", "2\\", s[1]);
 
+        // "" should become a single empty argument, same for ''
+        // PR 5906
+        s = Commandline.translateCommandline("\"\" a");
+        assertEquals("Doublequoted null arg prepend", 2, s.length);
+        assertEquals("Doublequoted null arg prepend", "", s[0]);
+        assertEquals("Doublequoted null arg prepend", "a", s[1]);
+        s = Commandline.translateCommandline("a \"\"");
+        assertEquals("Doublequoted null arg append", 2, s.length);
+        assertEquals("Doublequoted null arg append", "a", s[0]);
+        assertEquals("Doublequoted null arg append", "", s[1]);
+        s = Commandline.translateCommandline("\"\"");
+        assertEquals("Doublequoted null arg", 1, s.length);
+        assertEquals("Doublequoted null arg", "", s[0]);
+
+        s = Commandline.translateCommandline("\'\' a");
+        assertEquals("Singlequoted null arg prepend", 2, s.length);
+        assertEquals("Singlequoted null arg prepend", "", s[0]);
+        assertEquals("Singlequoted null arg prepend", "a", s[1]);
+        s = Commandline.translateCommandline("a \'\'");
+        assertEquals("Singlequoted null arg append", 2, s.length);
+        assertEquals("Singlequoted null arg append", "a", s[0]);
+        assertEquals("Singlequoted null arg append", "", s[1]);
+        s = Commandline.translateCommandline("\'\'");
+        assertEquals("Singlequoted null arg", 1, s.length);
+        assertEquals("Singlequoted null arg", "", s[0]);
 
         // now to the expected failures