/ is no longer a reserved char for urlEncode()

This change is a quick hack solving known issues with URI-encoding in
libkiwix.

This change removes the slash character from the list of URL separator
symbols in URL encoding/decoding utilities, and makes it a symbol that
is safe to leave unencoded.

Effects:

- `urlEncode()` never encodes the '/' symbol (even when it is requested
  to encode the URL separator symbols too).

- `urlDecode(str)`/`urlDecode(..., false)` will now decode %2F to '/';
  other encoded URL separator symbols are NOT decoded when the second
  argument of `urlDecode()` is set to false (which is the default).

src/tools/stringTools.cpp

@@ -172,7 +172,6 @@ bool isReservedUrlChar(char c)
   switch (c) {
   case ';':
   case ',':
-  case '/':
   case '?':
   case ':':
   case '@':
@@ -206,6 +205,7 @@ bool isHarmlessUriChar(char c)
   case '\'':
   case '(':
   case ')':
+  case '/':
     return true;
   }
   return false;

test/server.cpp

@@ -1156,7 +1156,7 @@ TEST_F(ServerTest, RandomPageRedirectsToAnExistingArticle)
   auto g = zfs1_->GET("/ROOT/random?content=zimfile");
   ASSERT_EQ(302, g->status);
   ASSERT_TRUE(g->has_header("Location"));
-  ASSERT_TRUE(kiwix::startsWith(g->get_header_value("Location"), "/ROOT/content/zimfile/A%2F"));
+  ASSERT_TRUE(kiwix::startsWith(g->get_header_value("Location"), "/ROOT/content/zimfile/A/"));
   ASSERT_EQ(getCacheControlHeader(*g), "max-age=0, must-revalidate");
   ASSERT_FALSE(g->has_header("ETag"));
 }
@@ -1224,7 +1224,7 @@ TEST_F(ServerTest, BookMainPageIsRedirectedToArticleIndex)
   auto g = zfs1_->GET("/ROOT/content/zimfile");
   ASSERT_EQ(302, g->status);
   ASSERT_TRUE(g->has_header("Location"));
-  ASSERT_EQ("/ROOT/content/zimfile/A%2Findex", g->get_header_value("Location"));
+  ASSERT_EQ("/ROOT/content/zimfile/A/index", g->get_header_value("Location"));
   }
 }
 

test/stringTools.cpp

@@ -110,8 +110,8 @@ namespace URLEncoding
 
 const char letters[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
 const char digits[] = "0123456789";
-const char nonEncodableSymbols[] = ".-_~()*!";
+const char nonEncodableSymbols[] = ".-_~()*!/";
-const char uriDelimSymbols[] = ":/@?=+&#$;,";
+const char uriDelimSymbols[] = ":@?=+&#$;,";
 
 const char otherSymbols[] = R"(`%^[]{}\|"<>)";
 
@@ -135,7 +135,7 @@ TEST(stringTools, urlEncode)
   EXPECT_EQ(urlEncode(nonEncodableSymbols, true), nonEncodableSymbols);
 
   EXPECT_EQ(urlEncode(uriDelimSymbols), uriDelimSymbols);
-  EXPECT_EQ(urlEncode(uriDelimSymbols, true), "%3A%2F%40%3F%3D%2B%26%23%24%3B%2C");
+  EXPECT_EQ(urlEncode(uriDelimSymbols, true), "%3A%40%3F%3D%2B%26%23%24%3B%2C");
 
   EXPECT_EQ(urlEncode(otherSymbols), "%60%25%5E%5B%5D%7B%7D%5C%7C%22%3C%3E");
   EXPECT_EQ(urlEncode(otherSymbols), urlEncode(otherSymbols, true));