fix URL-encode targets in -t browse

The browse tool did not correctly encode targets containing '%', causing them to be interpreted incorrectly after URL decoding.
Fix this by URL-encoding targets using urllib.parse.quote when generating links.

The import changes are compatible with both Python 2.7 and Python 3.x.

Additionally included a test to ensure complex target names are preserved exactly during parsing.

Fixes #2652

src/browse.py

@@ -37,9 +37,9 @@ if sys.version_info >= (3, 2):
 else:
     from cgi import escape
 try:
-    from urllib.request import unquote  # type: ignore # Module "urllib.request" has no attribute "unquote"
+    from urllib.parse import quote, unquote
 except ImportError:
-    from urllib2 import unquote
+    from urllib import quote, unquote
 from collections import namedtuple
 from typing import Tuple, Any
 
@@ -144,7 +144,7 @@ def generate_html(node: Node) -> str:
                 if type:
                     extra = ' (%s)' % html_escape(type)
                 document.append('<tt><a href="?%s">%s</a>%s</tt><br>' %
-                                (html_escape(input), html_escape(input), extra))
+                                (quote(input), html_escape(input), extra))
             document.append('</div>')
 
     if node.outputs:
@@ -152,7 +152,7 @@ def generate_html(node: Node) -> str:
         document.append('<div class=filelist>')
         for output in sorted(node.outputs):
             document.append('<tt><a href="?%s">%s</a></tt><br>' %
-                            (html_escape(output), html_escape(output)))
+                            (quote(output), html_escape(output)))
         document.append('</div>')
 
     return '\n'.join(document)

src/build_test.cc

@@ -4405,3 +4405,18 @@ TEST_F(BuildTest, ValidationWithCircularDependency) {
   EXPECT_FALSE(builder_.AddTarget("out", &err));
   EXPECT_EQ("dependency cycle: validate -> validate_in -> validate", err);
 }
+
+TEST_F(StateTestWithBuiltinRules, ComplexTargetPreserved) {
+  // Ensure targets containing spaces, percent-encoded sequences,
+  // and URL-reserved characters are preserved exactly during parsing.
+  ASSERT_NO_FATAL_FAILURE(AssertParse(&state_,
+    "rule copy\n"
+    "  command = cp $in $out\n"
+    "name = foo %2F bar?baz&x=1\n"
+    "build $name: copy foo\n"));
+
+  Node* node = state_.LookupNode("foo %2F bar?baz&x=1");
+  ASSERT_NE(node, nullptr);
+
+  EXPECT_EQ(node->path(), "foo %2F bar?baz&x=1");
+}