update_engine: Fix PReadAll and PWriteAll to be able to seek to 0.

Currently, we cannot Seek to 0 in a file in PReadAll/PWriteAll.
Seek returns the offset seeked if successful, so if the offset is
zero, this is cast to False in PRead/WriteAll and returns an error.

BUG=chromium:480751
TEST=`cros flash` image to itself, unit tests.

Change-Id: I1f49784256acd4e8309abf4ec3b30aae39d71ff6
Reviewed-on: https://chromium-review.googlesource.com/266983
Reviewed-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Allie Wood <alliewood@chromium.org>
Trybot-Ready: Allie Wood <alliewood@chromium.org>
Tested-by: Allie Wood <alliewood@chromium.org>
1 file changed
tree: 0005156cd9afe694c2b4feda0eb108c50cd94167
  1. dbus_bindings/
  2. init/
  3. payload_generator/
  4. update_manager/
  5. .gitignore
  6. action.h
  7. action_pipe.h
  8. action_pipe_unittest.cc
  9. action_processor.cc
  10. action_processor.h
  11. action_processor_unittest.cc
  12. action_unittest.cc
  13. bzip.cc
  14. bzip.h
  15. bzip_extent_writer.cc
  16. bzip_extent_writer.h
  17. bzip_extent_writer_unittest.cc
  18. certificate_checker.cc
  19. certificate_checker.h
  20. certificate_checker_unittest.cc
  21. chrome_browser_proxy_resolver.cc
  22. chrome_browser_proxy_resolver.h
  23. chrome_browser_proxy_resolver_unittest.cc
  24. clock.cc
  25. clock.h
  26. clock_interface.h
  27. connection_manager.cc
  28. connection_manager.h
  29. connection_manager_unittest.cc
  30. constants.cc
  31. constants.h
  32. dbus_constants.h
  33. dbus_service.cc
  34. dbus_service.h
  35. dbus_wrapper_interface.h
  36. delta_performer.cc
  37. delta_performer.h
  38. delta_performer_unittest.cc
  39. download_action.cc
  40. download_action.h
  41. download_action_unittest.cc
  42. error_code.h
  43. extent_ranges.cc
  44. extent_ranges.h
  45. extent_ranges_unittest.cc
  46. extent_writer.cc
  47. extent_writer.h
  48. extent_writer_unittest.cc
  49. fake_clock.h
  50. fake_file_writer.h
  51. fake_hardware.h
  52. fake_p2p_manager.h
  53. fake_p2p_manager_configuration.h
  54. fake_prefs.cc
  55. fake_prefs.h
  56. fake_system_state.cc
  57. fake_system_state.h
  58. file_descriptor.cc
  59. file_descriptor.h
  60. file_writer.cc
  61. file_writer.h
  62. file_writer_unittest.cc
  63. filesystem_copier_action.cc
  64. filesystem_copier_action.h
  65. filesystem_copier_action_unittest.cc
  66. glib_utils.cc
  67. glib_utils.h
  68. hardware.cc
  69. hardware.h
  70. hardware_interface.h
  71. http_common.cc
  72. http_common.h
  73. http_fetcher.cc
  74. http_fetcher.h
  75. http_fetcher_unittest.cc
  76. hwid_override.cc
  77. hwid_override.h
  78. hwid_override_unittest.cc
  79. install_plan.cc
  80. install_plan.h
  81. libcurl_http_fetcher.cc
  82. libcurl_http_fetcher.h
  83. local_coverage_rate
  84. main.cc
  85. metrics.cc
  86. metrics.h
  87. mock_action.h
  88. mock_action_processor.h
  89. mock_certificate_checker.h
  90. mock_connection_manager.h
  91. mock_dbus_wrapper.h
  92. mock_file_writer.h
  93. mock_hardware.h
  94. mock_http_fetcher.cc
  95. mock_http_fetcher.h
  96. mock_omaha_request_params.h
  97. mock_p2p_manager.h
  98. mock_payload_state.h
  99. mock_prefs.h
  100. mock_update_attempter.h
  101. mtd_file_descriptor.cc
  102. mtd_file_descriptor.h
  103. multi_range_http_fetcher.cc
  104. multi_range_http_fetcher.h
  105. omaha_hash_calculator.cc
  106. omaha_hash_calculator.h
  107. omaha_hash_calculator_unittest.cc
  108. omaha_request_action.cc
  109. omaha_request_action.h
  110. omaha_request_action_unittest.cc
  111. omaha_request_params.cc
  112. omaha_request_params.h
  113. omaha_request_params_unittest.cc
  114. omaha_response.h
  115. omaha_response_handler_action.cc
  116. omaha_response_handler_action.h
  117. omaha_response_handler_action_unittest.cc
  118. OWNERS
  119. p2p_manager.cc
  120. p2p_manager.h
  121. p2p_manager_unittest.cc
  122. payload_constants.cc
  123. payload_constants.h
  124. payload_state.cc
  125. payload_state.h
  126. payload_state_interface.h
  127. payload_state_unittest.cc
  128. payload_verifier.cc
  129. payload_verifier.h
  130. postinstall_runner_action.cc
  131. postinstall_runner_action.h
  132. postinstall_runner_action_unittest.cc
  133. prefs.cc
  134. prefs.h
  135. prefs_interface.h
  136. prefs_unittest.cc
  137. proxy_resolver.cc
  138. proxy_resolver.h
  139. real_dbus_wrapper.h
  140. real_system_state.cc
  141. real_system_state.h
  142. run_unittests
  143. sample_omaha_v3_response.xml
  144. subprocess.cc
  145. subprocess.h
  146. subprocess_unittest.cc
  147. system_state.h
  148. terminator.cc
  149. terminator.h
  150. terminator_unittest.cc
  151. test_http_server.cc
  152. test_utils.cc
  153. test_utils.h
  154. test_utils_unittest.cc
  155. testrunner.cc
  156. unittest_key.pem
  157. unittest_key2.pem
  158. update_attempter.cc
  159. update_attempter.h
  160. update_attempter_unittest.cc
  161. update_engine.conf
  162. update_engine.gyp
  163. update_engine_client.cc
  164. update_metadata.proto
  165. UpdateEngine.conf
  166. utils.cc
  167. utils.h
  168. utils_unittest.cc
  169. WATCHLISTS
  170. zip_unittest.cc