fix: new warnings (#2270)

* fix: avoid potential resource leak in metainfo test

Xref: https://scan5.coverity.com/reports.htm#v48014/p10174/fileInstanceId=205022335&defectInstanceId=52337396&mergedDefectId=1494638

* fix: use-init-statement warning

Xref: https://sonarcloud.io/project/issues?id=transmission_transmission&issues=AX2MsJ_lWODkx6cuASq6&open=AX2MsJ_lWODkx6cuASq6

* fix: omit-redundant-override-specifier warning

Xref: https://sonarcloud.io/project/issues?id=transmission_transmission&issues=AX2MsJ5GWODkx6cuASq5&open=AX2MsJ5GWODkx6cuASq5

* fix: improper-use-of-negative-value warning

Xref: https://scan5.coverity.com/reports.htm#v48014/p10174/fileInstanceId=205020121&defectInstanceId=52337394&mergedDefectId=1494639

* fix: unchecked return value warning

Xref: https://scan5.coverity.com/reports.htm#v48014/p10174/fileInstanceId=205020168&defectInstanceId=52304887&mergedDefectId=1491438

* fix: potential-divide-by-zero warning

Xref: https://scan5.coverity.com/reports.htm#v48014/p10174/fileInstanceId=205020106&defectInstanceId=52337395&mergedDefectId=1494438

libtransmission/block-info.h

@@ -39,7 +39,13 @@ struct tr_block_info
 
     constexpr tr_piece_index_t pieceForBlock(tr_block_index_t block) const
     {
-        return n_blocks_in_piece ? block / n_blocks_in_piece : 0;
+        // if not initialized yet, don't divide by zero
+        if (n_blocks_in_piece == 0)
+        {
+            return 0;
+        }
+
+        return block / n_blocks_in_piece;
     }
 
     constexpr uint32_t pieceSize(tr_piece_index_t piece) const
@@ -56,14 +62,36 @@ struct tr_block_info
 
     constexpr tr_piece_index_t pieceOf(uint64_t offset) const
     {
+        // if not initialized yet, don't divide by zero
+        if (piece_size == 0)
+        {
+            return 0;
+        }
+
         // handle 0-byte files at the end of a torrent
-        return offset == total_size ? n_pieces - 1 : offset / piece_size;
+        if (offset == total_size)
+        {
+            return n_pieces - 1;
+        }
+
+        return offset / piece_size;
     }
 
     constexpr tr_block_index_t blockOf(uint64_t offset) const
     {
+        // if not initialized yet, don't divide by zero
+        if (block_size == 0)
+        {
+            return 0;
+        }
+
         // handle 0-byte files at the end of a torrent
-        return offset == total_size ? n_blocks - 1 : offset / block_size;
+        if (offset == total_size)
+        {
+            return n_blocks - 1;
+        }
+
+        return offset / block_size;
     }
 
     constexpr uint64_t offset(tr_piece_index_t piece, uint32_t offset, uint32_t length = 0) const

libtransmission/torrent.h

@@ -248,7 +248,7 @@ public:
 
     /// WANTED
 
-    bool pieceIsWanted(tr_piece_index_t piece) const final override
+    bool pieceIsWanted(tr_piece_index_t piece) const final
     {
         return files_wanted_.pieceWanted(piece);
     }

libtransmission/tr-utp.cc

@@ -134,11 +134,11 @@ void tr_utpSendTo(void* closure, unsigned char const* buf, size_t buflen, struct
 
     if (to->sa_family == AF_INET && ss->udp_socket != TR_BAD_SOCKET)
     {
-        sendto(ss->udp_socket, reinterpret_cast<char const*>(buf), buflen, 0, to, tolen);
+        (void)sendto(ss->udp_socket, reinterpret_cast<char const*>(buf), buflen, 0, to, tolen);
     }
     else if (to->sa_family == AF_INET6 && ss->udp6_socket != TR_BAD_SOCKET)
     {
-        sendto(ss->udp6_socket, reinterpret_cast<char const*>(buf), buflen, 0, to, tolen);
+        (void)sendto(ss->udp6_socket, reinterpret_cast<char const*>(buf), buflen, 0, to, tolen);
     }
 }
 

libtransmission/utils.cc

@@ -384,8 +384,7 @@ bool tr_saveFile(char const* filename_in, std::string_view contents, tr_error**
 
     // follow symlinks to find the "real" file, to make sure the temporary
     // we build with tr_sys_file_open_temp() is created on the right partition
-    char* real_filename = tr_sys_path_resolve(filename.c_str(), nullptr);
-    if (real_filename != nullptr)
+    if (char* real_filename = tr_sys_path_resolve(filename.c_str(), nullptr); real_filename != nullptr)
     {
         filename = real_filename;
         tr_free(real_filename);

libtransmission/variant.cc

@@ -1207,16 +1207,18 @@ char* tr_variantToStr(tr_variant const* v, tr_variant_fmt fmt, size_t* len)
 
 int tr_variantToFile(tr_variant const* v, tr_variant_fmt fmt, char const* filename)
 {
+    auto error_code = int{ 0 };
     auto contents_len = size_t{};
     auto const* contents = tr_variantToStr(v, fmt, &contents_len);
     tr_error* error = nullptr;
-    auto const saved = tr_saveFile(filename, { contents, contents_len }, &error);
+    tr_saveFile(filename, { contents, contents_len }, &error);
     if (error != nullptr)
     {
         tr_logAddError(_("Error saving \"%s\": %s (%d)"), filename, error->message, error->code);
+        error_code = error->code;
         tr_error_clear(&error);
     }
-    return saved ? 0 : -1;
+    return error_code;
 }
 
 /***

tests/libtransmission/metainfo-test.cc

@@ -195,9 +195,12 @@ TEST(Metainfo, ctorSaveContents)
     auto* ctor = tr_ctorNew(nullptr);
     tr_error* error = nullptr;
     EXPECT_FALSE(tr_ctorSaveContents(ctor, tgt_filename.c_str(), &error));
-    ASSERT_NE(nullptr, error);
-    EXPECT_EQ(EINVAL, error->code);
-    tr_error_clear(&error);
+    EXPECT_NE(nullptr, error);
+    if (error != nullptr)
+    {
+        EXPECT_EQ(EINVAL, error->code);
+        tr_error_clear(&error);
+    }
 
     // now try saving _with_ metainfo
     EXPECT_EQ(0, tr_ctorSetMetainfoFromFile(ctor, src_filename.c_str()));