Fix minor warnings and documentation typos (#666)

Build warnings could be seen [here](https://buildd.debian.org/status/fetch.php?pkg=c-ares&arch=arm64&ver=1.24.0-1&stamp=1702826366&raw=0) [origin](https://buildd.debian.org/status/package.php?p=c-ares)

Fix By: Gregor Jasny (@gjasny)

INSTALL.md

@@ -32,7 +32,7 @@ the same for both Git and official release tarballs.
 AutoTools Build
 ===============
 
-### General Information, works on most Unix Platforms (Linux, FreeBSD, etc)
+### General Information, works on most Unix Platforms (Linux, FreeBSD, etc.)
 
 A normal Unix installation is made in three or four steps (after you've
 unpacked the source archive):
@@ -57,7 +57,7 @@ you need to specify that already when running configure:
 
 If you happen to have write permission in that directory, you can do `make
 install` without being root. An example of this would be to make a local
-install in your own home directory:
+installation in your own home directory:
 
     ./configure --prefix=$HOME
     make
@@ -183,7 +183,7 @@ Method using a configure cross-compile (tested with Android NDK r7b):
 
         ./tools/make-standalone-toolchain.sh
 
-    which creates a usual cross-compile toolchain. Lets assume that you put
+    which creates a usual cross-compile toolchain. Let's assume that you put
     this toolchain below `/opt` then invoke configure with something
     like:
 
@@ -213,7 +213,7 @@ CMake builds
 ============
 
 Current releases of c-ares introduce a CMake v3+ build system that has been
-tested on most platforms including Windows, Linux, FreeBSD, MacOS, AIX and
+tested on most platforms including Windows, Linux, FreeBSD, macOS, AIX and
 Solaris.
 
 In the most basic form, building with CMake might look like:
@@ -233,12 +233,17 @@ Options
 Options to CMake are passed on the command line using "-D${OPTION}=${VALUE}".
 The values defined are all boolean and take values like On, Off, True, False.
 
-* CARES_STATIC - Build the static library (off by default)
-* CARES_SHARED - Build the shared library (on by default)
-* CARES_INSTALL - Hook in installation, useful to disable if chain building
-* CARES_STATIC_PIC - Build the static library as position-independent (off by
-   default)
-
+| Option Name                 | Description                                                           | Default Value  |
+|-----------------------------|-----------------------------------------------------------------------|----------------|
+| CARES_STATIC                | Build the static library                                              | Off            |
+| CARES_SHARED                | Build the shared library                                              | On             |
+| CARES_INSTALL               | Hook in installation, useful to disable if chain building             | On             |
+| CARES_STATIC_PIC            | Build the static library as position-independent                      | Off            |
+| CARES_BUILD_TESTS           | Build and run tests                                                   | Off            |
+| CARES_BUILD_CONTAINER_TESTS | Build and run container tests (implies CARES_BUILD_TESTS, Linux only) | Off            |
+| CARES_BUILD_TOOLS           | Build tools                                                           | On             |
+| CARES_SYMBOL_HIDING         | Hide private symbols in shared libraries                              | Off            |
+| CARES_THREADS               | Build with thread-safety support                                      | On             |
 
 Ninja
 -----

README.md

@@ -49,7 +49,7 @@ Notes for c-ares hackers
 
 * If you intend to distribute an already compiled c-ares library you **MUST**
   also distribute along with it the generated `ares_build.h` which has been
-  used to compile it. Otherwise the library will be of no use for the users of
+  used to compile it. Otherwise, the library will be of no use for the users of
   the library that you have built. It is **your** responsibility to provide this
   file. No one at the c-ares project can know how you have built the library.
 

src/lib/ares__htable.c

@@ -46,7 +46,7 @@ struct ares__htable {
    *       hash collisions we would have O(log n) worst case insert and search
    *       performance.  (We'd also need to make key_eq into a key_cmp to
    *       support sort).  That said, risk with a random hash seed is near zero,
-   *       and ares__slist_t is heavier weight so I think using ares__llist_t is
+   *       and ares__slist_t is heavier weight, so I think using ares__llist_t
    *       is an overall win. */
   ares__llist_t            **buckets;
 };

test/ares-test-internal.cc

@@ -235,7 +235,7 @@ TEST_F(LibraryTest, FreeCorruptData) {
   void* p = &(data->data);
 
   // Invalid type
-  data->type = (ares_datatype)99;
+  data->type = (ares_datatype)ARES_DATATYPE_LAST;
   data->mark = ARES_DATATYPE_MARK;
   ares_free_data(p);
 

test/ares-test-misc.cc

@@ -351,8 +351,8 @@ TEST_F(DefaultChannelTest, SendFailure) {
   EXPECT_EQ(ARES_EBADQUERY, result.status_);
 }
 
-std::string ExpandName(const std::vector<byte>& data, int offset,
-                       long *enclen) {
+static std::string ExpandName(const std::vector<byte>& data, int offset,
+                              long *enclen) {
   char *name = nullptr;
   int rc = ares_expand_name(data.data() + offset, data.data(), (int)data.size(),
                             &name, enclen);

test/ares-test.cc

@@ -376,8 +376,8 @@ void MockServer::ProcessPacket(ares_socket_t fd, struct sockaddr_storage *addr,
               << ")" << std::endl;
     return;
   }
-  byte* question = data + 12;
-  int qlen = len - 12;
+  byte* question = data + NS_HFIXEDSZ;
+  int qlen = len - NS_HFIXEDSZ;
 
   char *name = nullptr;
   long enclen;
@@ -386,7 +386,11 @@ void MockServer::ProcessPacket(ares_socket_t fd, struct sockaddr_storage *addr,
     std::cerr << "Failed to retrieve name" << std::endl;
     return;
   }
-  qlen -= enclen;
+  if (enclen > qlen) {
+    std::cerr << "(error, encoded name len " << enclen << "bigger than remaining data " << qlen << " bytes)" << std::endl;
+    return;
+  }
+  qlen -= (int)enclen;
   question += enclen;
   std::string namestr(name);
   ares_free_string(name);

test/dns-proto.cc

@@ -270,7 +270,7 @@ std::string QuestionToString(const std::vector<byte>& packet,
     ss << "(error, encoded name len " << enclen << "bigger than remaining data " << *len << " bytes)";
     return ss.str();
   }
-  *len -= enclen;
+  *len -= (int)enclen;
   *data += enclen;
   ss << "'" << name << "' ";
   ares_free_string(name);
@@ -306,7 +306,7 @@ std::string RRToString(const std::vector<byte>& packet,
     ss << "(error, encoded name len " << enclen << "bigger than remaining data " << *len << " bytes)";
     return ss.str();
   }
-  *len -= enclen;
+  *len -= (int)enclen;
   *data += enclen;
   ss << "'" << name << "' ";
   ares_free_string(name);