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Re: [PATCH v5 04/15] git-p4: change the expansion test from basestring to list

From
Junio C Hamano <gitster@pobox.com>
Date
Dec 9, 2019, 20:25 UTC
Message-ID
<xmqq8snlutyx.fsf@gitster-ct.c.googlers.com>
In-Reply-To
<7170aface2270e8c46439c5c1e01d2b18cdf6fd0.1575740863.git.gitgitgadget@gmail.com>
"Ben Keene via GitGitGadget" <gitgitgadget@gmail.com> writes:
> The original code used 'basestring' in a test to determine if a list or
> literal string was passed into 9 different functions.  This is used to

s/literal/a &/, probably, but I do not thin this is about "literal" at all. Perhaps "if a list or a string was passed ..." is what you meant, as the code seems to have two ways to represent a command line in the program, one as a single string with possibly multiple tokens on it, separated with IFS and quoted just like you would feed to shell, and the other as a list of strings, each element being a single argv[] element for the command to be invoked.

So the issue is that isinstance(X, basestring) used to be how you are supposed to see if X is a "string", and the logic were built around "if we have a string, then keep the command in a string when manipulating, and otherwise what we have must be a command line in a list". But because Unicode string is not an instance of basestring, the logic no longer work, so you'd flip the polarity around to use "if it is not a list, then we must have a command in a string".

Which makes sense.
> determine if the shell should be invoked when calling subprocess
> methods.

This is mostly true, but the use in p4_build_cmd() and the second use among the two uses in p4CmdList() are different.

	Some codepaths can represent a command line the program
	internally prepares to execute either as a single string
	(i.e. each token properly quoted, concatenated with $IFS) or
	as a list of argv[] elements, and there are 9 places where
	we say "if X is isinstance(_, basestring), then do this
	thing to handle X as a command line in a single string; if
	not, X is a command line in a list form".
	This does not work well with Python 3, as there is no
	basestring (everything is Unicode now), and even with Python
	2, it was not an ideal way to tell the two cases apart,
	because an internally formed command line could have been in
	a single Unicode string.
	Flip the check to say "if X is not a list, then handle X as
	a command line in a single string; otherwise treat it as a
	command line in a list form".
	This will get rid of references to 'basestring', to migrate
	the code ready for Python 3.
or something like that?
Previous: Ben Keene via GitGitGadgetNext: Ben Keene
Message 55 of 77 in “git-p4.py: Cast byte strings to unicode strings in python3”
  1. 0/1 git-p4.py: Cast byte strings to unicode strings in python3Ben Keene via GitGitGadget, Nov 13, 2019
  2. 1/1 Cast byte strings to unicode strings in python3Ben Keene via GitGitGadget, Nov 13, 2019
  3. Junio C HamanoNov 14, 2019
  4. Luke DiamandNov 14, 2019
  5. 0/3 git-p4.py: Cast byte strings to unicode strings in python3Ben Keene via GitGitGadget, Nov 15, 2019
  6. 1/3 Cast byte strings to unicode strings in python3Ben Keene via GitGitGadget, Nov 15, 2019
  7. 2/3 FIX: cast as unicode fails when a value is already unicodeBen Keene via GitGitGadget, Nov 15, 2019
  8. 3/3 FIX: wrap return for read_pipe_lines in ustring() and wrap GitLFS read of the pointer file in ustring()Ben Keene via GitGitGadget, Nov 15, 2019
  9. 0/1 git-p4.py: Cast byte strings to unicode strings in python3Ben Keene via GitGitGadget, Dec 2, 2019
  10. 1/1 Python3 support for t9800 tests. Basic P4/Python3 supportBen Keene via GitGitGadget, Dec 2, 2019
  11. Denton LiuDec 3, 2019
  12. Ben KeeneDec 3, 2019
  13. Denton LiuDec 4, 2019
  14. 00/11 git-p4.py: Cast byte strings to unicode strings in python3Ben Keene via GitGitGadget, Dec 4, 2019
  15. 01/11 git-p4: select p4 binary by operating-systemBen Keene via GitGitGadget, Dec 4, 2019
  16. Denton LiuDec 5, 2019
  17. Ben KeeneDec 5, 2019
  18. 02/11 git-p4: change the expansion test from basestring to listBen Keene via GitGitGadget, Dec 4, 2019
  19. Denton LiuDec 5, 2019
  20. Ben KeeneDec 5, 2019
  21. 03/11 git-p4: add new helper functions for python3 conversionBen Keene via GitGitGadget, Dec 4, 2019
  22. Denton LiuDec 5, 2019
  23. Ben KeeneDec 5, 2019
  24. 05/11 git-p4: Add new functions in preparation of usageBen Keene via GitGitGadget, Dec 4, 2019
  25. Denton LiuDec 5, 2019
  26. Ben KeeneDec 5, 2019
  27. 04/11 git-p4: python3 syntax changesBen Keene via GitGitGadget, Dec 4, 2019
  28. Denton LiuDec 5, 2019
  29. 08/11 git-p4: p4CmdList - support Unicode encodingBen Keene via GitGitGadget, Dec 4, 2019
  30. Junio C HamanoDec 5, 2019
  31. Ben KeeneDec 5, 2019
  32. 07/11 git-p4: Add a helper class for stream writingBen Keene via GitGitGadget, Dec 4, 2019
  33. Junio C HamanoDec 5, 2019
  34. Ben KeeneDec 5, 2019
  35. 06/11 git-p4: Fix assumed path separators to be more Windows friendlyBen Keene via GitGitGadget, Dec 4, 2019
  36. Junio C HamanoDec 5, 2019
  37. Ben KeeneDec 5, 2019
  38. 09/11 git-p4: Add usability enhancementsBen Keene via GitGitGadget, Dec 4, 2019
  39. Junio C HamanoDec 5, 2019
  40. Ben KeeneDec 5, 2019
  41. 10/11 git-p4: Support python3 for basic P4 clone, sync, and submitBen Keene via GitGitGadget, Dec 4, 2019
  42. 11/11 git-p4: Added --encoding parameter to p4 cloneBen Keene via GitGitGadget, Dec 4, 2019
  43. Luke DiamandDec 5, 2019
  44. Ben KeeneDec 5, 2019
  45. Denton LiuDec 5, 2019
  46. Ben KeeneDec 5, 2019
  47. 00/15 git-p4.py: Cast byte strings to unicode strings in python3Ben Keene via GitGitGadget, Dec 7, 2019
  48. 01/15 t/gitweb-lib.sh: drop confusing quotesJeff King via GitGitGadget, Dec 7, 2019
  49. 02/15 t/gitweb-lib.sh: set $REQUEST_URIJeff King via GitGitGadget, Dec 7, 2019
  50. 03/15 git-p4: select P4 binary by operating-systemBen Keene via GitGitGadget, Dec 7, 2019
  51. Junio C HamanoDec 9, 2019
  52. 05/15 git-p4: promote encodeWithUTF8() to a global functionBen Keene via GitGitGadget, Dec 7, 2019
  53. Junio C HamanoDec 11, 2019
  54. 04/15 git-p4: change the expansion test from basestring to listBen Keene via GitGitGadget, Dec 7, 2019
  55. Junio C HamanoDec 9, 2019
  56. Ben KeeneDec 13, 2019
  57. 06/15 git-p4: remove p4_write_pipe() and write_pipe() return valuesBen Keene via GitGitGadget, Dec 7, 2019
  58. 11/15 git-p4: add Py23File() - helper class for stream writingBen Keene via GitGitGadget, Dec 7, 2019
  59. 08/15 git-p4: add casting helper functions for python 3 conversionBen Keene via GitGitGadget, Dec 7, 2019
  60. 09/15 git-p4: python 3 syntax changesBen Keene via GitGitGadget, Dec 7, 2019
  61. 10/15 git-p4: fix assumed path separators to be more Windows friendlyBen Keene via GitGitGadget, Dec 7, 2019
  62. 15/15 git-p4: Add depot manipulation functionsBen Keene via GitGitGadget, Dec 7, 2019
  63. 14/15 git-p4: added --encoding parameter to p4 cloneBen Keene via GitGitGadget, Dec 7, 2019
  64. 07/15 git-p4: add new support function gitConfigSet()Ben Keene via GitGitGadget, Dec 7, 2019
  65. Junio C HamanoDec 11, 2019
  66. 13/15 git-p4: support Python 3 for basic P4 clone, sync, and submit (t9800)Ben Keene via GitGitGadget, Dec 7, 2019
  67. 12/15 git-p4: p4CmdList - support Unicode encodingBen Keene via GitGitGadget, Dec 7, 2019
  68. Jeff KingDec 7, 2019
  69. Ben KeeneDec 7, 2019
  70. Junio C HamanoDec 11, 2019
  71. Denton LiuDec 11, 2019
  72. Junio C HamanoDec 11, 2019
  73. Luke DiamandDec 11, 2019
  74. Junio C HamanoDec 11, 2019
  75. Yang ZhaoDec 11, 2019
  76. Ben KeeneDec 12, 2019
  77. Ben KeeneDec 13, 2019

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