pw_rpc: Fix responding with empty buffers

The Channel::OutputBuffer::Contains() method previously did not check if
the OutputBuffer itself was empty. An empty span sent as a raw response
would appear as a span within the OutputBuffer, even though the
OutputBuffer was never allocated. Instead of allocating an OutputBuffer
for the RPC packet, the responder would attempt to encode it into the
empty OutputBuffer, which would fail.

- Update Contains() so it returns false on an empty OutputBuffer.
- Add tests for OutputBuffer::Contains() and sending an empty response.

Change-Id: I089944079655ed6c21f40c8f19c1d94b942ebdd8
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/53420
Reviewed-by: Alexei Frolov <frolv@google.com>
Commit-Queue: Wyatt Hepler <hepler@google.com>
5 files changed
tree: e0ce74dd661dbd81edcbb1fbcaa5dc1f165728a1
  1. build_overrides/
  2. docker/
  3. docs/
  4. pw_allocator/
  5. pw_analog/
  6. pw_arduino_build/
  7. pw_assert/
  8. pw_assert_basic/
  9. pw_assert_log/
  10. pw_base64/
  11. pw_bloat/
  12. pw_blob_store/
  13. pw_boot_armv7m/
  14. pw_build/
  15. pw_bytes/
  16. pw_checksum/
  17. pw_chrono/
  18. pw_chrono_embos/
  19. pw_chrono_freertos/
  20. pw_chrono_stl/
  21. pw_chrono_threadx/
  22. pw_cli/
  23. pw_console/
  24. pw_containers/
  25. pw_cpu_exception/
  26. pw_cpu_exception_cortex_m/
  27. pw_crypto/
  28. pw_docgen/
  29. pw_doctor/
  30. pw_env_setup/
  31. pw_function/
  32. pw_fuzzer/
  33. pw_hdlc/
  34. pw_hex_dump/
  35. pw_i2c/
  36. pw_interrupt/
  37. pw_interrupt_cortex_m/
  38. pw_kvs/
  39. pw_libc/
  40. pw_log/
  41. pw_log_basic/
  42. pw_log_multisink/
  43. pw_log_null/
  44. pw_log_rpc/
  45. pw_log_sink/
  46. pw_log_tokenized/
  47. pw_malloc/
  48. pw_malloc_freelist/
  49. pw_metric/
  50. pw_minimal_cpp_stdlib/
  51. pw_module/
  52. pw_multisink/
  53. pw_package/
  54. pw_persistent_ram/
  55. pw_polyfill/
  56. pw_preprocessor/
  57. pw_presubmit/
  58. pw_protobuf/
  59. pw_protobuf_compiler/
  60. pw_random/
  61. pw_result/
  62. pw_ring_buffer/
  63. pw_router/
  64. pw_rpc/
  65. pw_snapshot/
  66. pw_span/
  67. pw_status/
  68. pw_stm32cube_build/
  69. pw_stream/
  70. pw_string/
  71. pw_sync/
  72. pw_sync_baremetal/
  73. pw_sync_embos/
  74. pw_sync_freertos/
  75. pw_sync_stl/
  76. pw_sync_threadx/
  77. pw_sys_io/
  78. pw_sys_io_arduino/
  79. pw_sys_io_baremetal_lm3s6965evb/
  80. pw_sys_io_baremetal_stm32f429/
  81. pw_sys_io_stdio/
  82. pw_target_runner/
  83. pw_thread/
  84. pw_thread_embos/
  85. pw_thread_freertos/
  86. pw_thread_stl/
  87. pw_thread_threadx/
  88. pw_tls_client/
  89. pw_tls_client_boringssl/
  90. pw_tls_client_mbedtls/
  91. pw_tokenizer/
  92. pw_tool/
  93. pw_toolchain/
  94. pw_trace/
  95. pw_trace_tokenized/
  96. pw_transfer/
  97. pw_unit_test/
  98. pw_varint/
  99. pw_watch/
  100. pw_web_ui/
  101. targets/
  102. third_party/
  103. .bazelignore
  104. .bazelrc
  105. .clang-format
  106. .eslintrc.json
  107. .gitattributes
  108. .gitignore
  109. .gn
  110. .prettierrc.js
  111. .pylintrc
  112. activate.bat
  113. AUTHORS
  114. bootstrap.bat
  115. bootstrap.sh
  116. BUILD.bazel
  117. BUILD.gn
  118. BUILDCONFIG.gn
  119. CMakeLists.txt
  120. LICENSE
  121. modules.gni
  122. OWNERS
  123. package.json
  124. PW_PLUGINS
  125. README.md
  126. tsconfig.json
  127. WORKSPACE
  128. yarn.lock
README.md

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