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, 5 insertions, 3 deletions

diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index db3934d5e..f252b449c 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -1315,10 +1315,12 @@ StorePath LocalStore::addToStoreFromDump(Source & source0, std::string_view name
         auto oldSize = dump.size();
         constexpr size_t chunkSize = 65536;
         auto want = std::min(chunkSize, settings.narBufferSize - oldSize);
-        if (auto tmp = realloc(dumpBuffer.get(), oldSize + want)) {
-            dumpBuffer.release();
-            dumpBuffer.reset((char*) tmp);
+
+        auto *toRealloc = dumpBuffer.release();
+        if (auto realloced = realloc(toRealloc, oldSize + want)) {
+            dumpBuffer.reset((char*) realloced);
         } else {
+            free(toRealloc);
             throw std::bad_alloc();
         }
         auto got = 0;