Fix various clang-tidy lints

* some things that can throw are marked noexcept
  yet the linter seems to think not. Maybe they can't throw in practice.
  I would rather not have the UB possibility in pretty obvious cold
  paths.
* various default-case-missing complaints
* a fair pile of casts from integer to character, which are in fact
  deliberate.
* an instance of <https://clang.llvm.org/extra/clang-tidy/checks/bugprone/move-forwarding-reference.html>
* bugprone-not-null-terminated-result on handing a string to curl in
  chunks of bytes. our usage is fine.
* reassigning a unique_ptr by CRIMES instead of using release(), then
  using release() and ignoring the result. wild. let's use release() for
  its intended purpose.

Change-Id: Ic3e7affef12383576213a8a7c8145c27e662513d

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libstore/filetransfer.cc b/src/libstore/filetransfer.cc
index b843a95f9..ef2480863 100644
--- a/src/libstore/filetransfer.cc
+++ b/src/libstore/filetransfer.cc
@@ -142,7 +142,7 @@ struct curlFileTransfer : public FileTransfer
         template<class T>
         void fail(T && e)
         {
-            failEx(std::make_exception_ptr(std::move(e)));
+            failEx(std::make_exception_ptr(std::forward<T>(e)));
         }
 
         LambdaSink finalSink;
@@ -270,6 +270,9 @@ struct curlFileTransfer : public FileTransfer
                 return 0;
             auto count = std::min(size * nitems, request.data->length() - readOffset);
             assert(count);
+            // Lint: this is turning a string into a byte array to hand to
+            // curl, which is fine.
+            // NOLINTNEXTLINE(bugprone-not-null-terminated-result)
             memcpy(buffer, request.data->data() + readOffset, count);
             readOffset += count;
             return count;