GH-49435: [CI][C++] Fix macOS build with Homebrew protobuf v34 (#49491)

### Rationale for this change
Closes #49435

### What changes are included in this PR?
a) Add brew update to `cpp.yml` and `python.yml` for GitHub Actions runner to use updated formulae
b) Handle 'nodiscard' return values in Flight and Substrait

See grpc/grpc#41755
(See also previous discussion in [#49436](#49436 (comment)))

### Are these changes tested?
Yes, macOS C++ and Python CI jobs pass.

### Are there any user-facing changes?
No.
* GitHub Issue: #49435

Lead-authored-by: Tadeja Kadunc <tadeja.kadunc@gmail.com>
Co-authored-by: tadeja <tadeja@users.noreply.github.com>
Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
Signed-off-by: Raúl Cumplido <raulcumplido@gmail.com>

Author: tadeja

.github/workflows/cpp.yml

@@ -229,6 +229,9 @@ jobs:
           # pkg-config formula is removed from GitHub Actions runner.
           brew uninstall pkg-config || :
           brew uninstall pkg-config@0.29.2 || :
+          # Workaround for https://github.com/grpc/grpc/issues/41755
+          # Remove once the runner ships a newer Homebrew.
+          brew update
           brew bundle --file=cpp/Brewfile
       - name: Install MinIO
         run: |

.github/workflows/python.yml

@@ -199,8 +199,10 @@ jobs:
           # pkg-config formula is removed from GitHub Actions runner.
           brew uninstall pkg-config || :
           brew uninstall pkg-config@0.29.2 || :
+          # Workaround for https://github.com/grpc/grpc/issues/41755
+          # Remove once the runner ships a newer Homebrew.
+          brew update
           brew bundle --file=cpp/Brewfile
-
           python -m pip install \
             -r python/requirements-build.txt \
             -r python/requirements-test.txt

cpp/src/arrow/engine/substrait/expression_internal.cc

@@ -804,7 +804,13 @@ struct ScalarToProtoImpl {
     auto user_defined = std::make_unique<Lit::UserDefined>();
     user_defined->set_type_reference(anchor);
     auto value_any = std::make_unique<google::protobuf::Any>();
+#if PROTOBUF_VERSION >= 3015000
+    if (!value_any->PackFrom(value)) {
+      return Status::IOError("Failed to pack user-defined type value");
+    }
+#else
     value_any->PackFrom(value);
+#endif
     user_defined->set_allocated_value(value_any.release());
     lit_->set_allocated_user_defined(user_defined.release());
     return Status::OK();

cpp/src/arrow/engine/substrait/options.cc

@@ -68,17 +68,23 @@ class DefaultExtensionProvider : public BaseExtensionProvider {
                                   const ExtensionSet& ext_set) override {
     if (rel.Is<substrait_ext::AsOfJoinRel>()) {
       substrait_ext::AsOfJoinRel as_of_join_rel;
-      rel.UnpackTo(&as_of_join_rel);
+      if (!rel.UnpackTo(&as_of_join_rel)) {
+        return Status::IOError("Failed to unpack AsOfJoinRel");
+      }
       return MakeAsOfJoinRel(inputs, as_of_join_rel, ext_set);
     }
     if (rel.Is<substrait_ext::NamedTapRel>()) {
       substrait_ext::NamedTapRel named_tap_rel;
-      rel.UnpackTo(&named_tap_rel);
+      if (!rel.UnpackTo(&named_tap_rel)) {
+        return Status::IOError("Failed to unpack NamedTapRel");
+      }
       return MakeNamedTapRel(conv_opts, inputs, named_tap_rel, ext_set);
     }
     if (rel.Is<substrait_ext::SegmentedAggregateRel>()) {
       substrait_ext::SegmentedAggregateRel seg_agg_rel;
-      rel.UnpackTo(&seg_agg_rel);
+      if (!rel.UnpackTo(&seg_agg_rel)) {
+        return Status::IOError("Failed to unpack SegmentedAggregateRel");
+      }
       return MakeSegmentedAggregateRel(conv_opts, inputs, seg_agg_rel, ext_set);
     }
     return Status::NotImplemented("Unrecognized extension in Substrait plan: ",

cpp/src/arrow/flight/sql/server.cc

@@ -537,7 +537,13 @@ arrow::Result<std::string> CreateStatementQueryTicket(
   ticket_statement_query.set_statement_handle(statement_handle);
 
   google::protobuf::Any ticket;
+#if PROTOBUF_VERSION >= 3015000
+  if (!ticket.PackFrom(ticket_statement_query)) {
+    return Status::IOError("Failed to pack ticket");
+  }
+#else
   ticket.PackFrom(ticket_statement_query);
+#endif
 
   std::string ticket_string;
 

cpp/src/arrow/flight/transport/grpc/serialization_internal.cc

@@ -353,7 +353,10 @@ ::grpc::Status FlightDataDeserialize(ByteBuffer* buffer,
         // Can't use ParseFromCodedStream as this reads the entire
         // rest of the stream into the descriptor command field.
         std::string buffer;
-        pb_stream.ReadString(&buffer, length);
+        if (!pb_stream.ReadString(&buffer, length)) {
+          return {::grpc::StatusCode::INTERNAL,
+                  "Unable to read FlightDescriptor from protobuf"};
+        }
         if (!pb_descriptor.ParseFromString(buffer)) {
           return {::grpc::StatusCode::INTERNAL, "Unable to parse FlightDescriptor"};
         }