Merge pull request #231 from yaoweibin/fix_unescape_uri

it looks good to me

src/core/ngx_string.c

@@ -1622,7 +1622,7 @@ ngx_unescape_uri(u_char **dst, u_char **src, size_t size, ngx_uint_t type)
 
             state = sw_usual;
 
-            *d++ = ch;
+            *d++ = '%'; *d++ = ch;
 
             break;
 
@@ -1685,6 +1685,7 @@ ngx_unescape_uri(u_char **dst, u_char **src, size_t size, ngx_uint_t type)
 
             /* the invalid quoted character */
 
+            *d++ = '%'; *d++ = *(s - 2); *d++ = *(s - 1);
             break;
         }
     }

tests/nginx-tests/cases/string.t

@@ -0,0 +1,83 @@
+#!/usr/bin/perl
+
+# Tests for string.c.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+
+BEGIN { use FindBin; chdir($FindBin::Bin); }
+
+use lib 'lib';
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+my $t = Test::Nginx->new()->plan(4);
+
+$t->set_dso("ngx_http_fastcgi_module", "ngx_http_fastcgi_module.so");
+$t->set_dso("ngx_http_uwsgi_module", "ngx_http_uwsgi_module.so");
+$t->set_dso("ngx_http_scgi_module", "ngx_http_scgi_module.so");
+$t->set_dso("ngx_http_upstream_ip_hash_module", "ngx_http_upstream_ip_hash_module.so");
+$t->set_dso("ngx_http_upstream_least_conn_module", "ngx_http_upstream_least_conn_module.so");
+
+$t->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon         off;
+
+%%TEST_GLOBALS_DSO%%
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location /good {
+            #output: s%20elect
+            rewrite .* http://127.0.0.1/s%20elect;
+        }
+
+        location /good1 {
+            #output: s&elect
+            rewrite .* http://127.0.0.1/s%26elect;
+        }
+
+        location /invalid {
+            #output: s%elect
+            rewrite .* http://127.0.0.1/s%elect;
+        }
+
+        location /invalid1 {
+            #output: se%lect
+            rewrite .* http://127.0.0.1/se%lect;
+        }
+    }
+}
+
+EOF
+
+$t->write_file('index.html', 'hello, tengine!');
+
+$t->run();
+
+###############################################################################
+
+like(http_get('/good'), qr/s%20elect/, 'good');
+like(http_get('/good1'), qr/s&elect/,  'good1');
+like(http_get('/invalid'), qr/s%elect/, 'invalid');
+like(http_get('/invalid1'), qr/se%lect/, 'invalid1');
+
+###############################################################################