view tests/test-hgweb-annotate-whitespace.t @ 46607:e9901d01d135

revlog: add a mechanism to verify expected file position before appending

If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.

The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)

When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.

For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.

This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.

Differential Revision: https://phab.mercurial-scm.org/D9952

#require serve

Create a repo with whitespace only changes

  $ hg init repo-with-whitespace
  $ cd repo-with-whitespace
  $ cat > foo << EOF
  > line 0
  > line 1
  > line 2
  > line 3
  > EOF
  $ hg -q commit -A -m 'commit 0'
  $ cat > foo << EOF
  > line 0
  > line 1 modified by 1
  > line 2
  > line 3
  > EOF
  $ hg commit -m 'commit 1'
  $ cat > foo << EOF
  > line 0
  > line 1 modified by 1
  >     line 2
  > line 3
  > EOF
  $ hg commit -m 'commit 2 (leading whitespace on line 2)'
  $ cat > foo << EOF
  > line 0
  > line 1 modified by 1
  >     line 2
  > EOF
Need to use printf to avoid check-code complaining about trailing whitespace.
  $ printf 'line 3    \n' >> foo
  $ hg commit -m 'commit 3 (trailing whitespace on line 3)'
  $ cat > foo << EOF
  > line  0
  > line 1 modified by 1
  >     line 2
  > EOF
  $ printf 'line 3    \n' >> foo
  $ hg commit -m 'commit 4 (intra whitespace on line 0)'
  $ cat > foo << EOF
  > line  0
  > 
  > line 1 modified by 1
  >     line 2
  > EOF
  $ printf 'line 3    \n' >> foo
  $ hg commit -m 'commit 5 (add blank line between line 0 and 1)'
  $ cat > foo << EOF
  > line  0
  > 
  > 
  > line 1 modified by 1
  >     line 2
  > EOF
  $ printf 'line 3    \n' >> foo
  $ hg commit -m 'commit 6 (add another blank line between line 0 and 1)'

  $ hg log -G -T '{rev}:{node|short} {desc}'
  @  6:9d1b2c7db017 commit 6 (add another blank line between line 0 and 1)
  |
  o  5:400ef1d40470 commit 5 (add blank line between line 0 and 1)
  |
  o  4:08adbe269f24 commit 4 (intra whitespace on line 0)
  |
  o  3:dcb62cfbfc9b commit 3 (trailing whitespace on line 3)
  |
  o  2:6bdb694e7b8c commit 2 (leading whitespace on line 2)
  |
  o  1:23e1e37387dc commit 1
  |
  o  0:b9c578134d72 commit 0
  

  $ hg serve -p $HGPORT -d --pid-file hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ hg serve --config annotate.ignorews=true -p $HGPORT1 -d --pid-file hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ cd ..

Annotate works

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 4 (intra whitespace on line 0)",
        "line": "line  0\n",
        "lineno": 1,
        "node": "08adbe269f24cf22d975eadeec16790c5b22f558",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 3 (trailing whitespace on line 3)",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "dcb62cfbfc9b3ab995a5cbbaff6e1971c3e4f865",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

annotate.ignorews=1 config option is honored

  $ get-with-headers.py --json $LOCALIP:$HGPORT1 'json-annotate/9d1b2c7db017/foo'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line  0\n",
        "lineno": 1,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignorews=1 query string argument enables whitespace skipping

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo?ignorews=1'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line  0\n",
        "lineno": 1,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignorews=0 query string argument disables when config defaults to enabled

  $ get-with-headers.py --json $LOCALIP:$HGPORT1 'json-annotate/9d1b2c7db017/foo?ignorews=0'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 4 (intra whitespace on line 0)",
        "line": "line  0\n",
        "lineno": 1,
        "node": "08adbe269f24cf22d975eadeec16790c5b22f558",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 3 (trailing whitespace on line 3)",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "dcb62cfbfc9b3ab995a5cbbaff6e1971c3e4f865",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignorewsamount=1 query string enables whitespace amount skipping

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo?ignorewsamount=1'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line  0\n",
        "lineno": 1,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignorewseol=1 query string enables whitespace end of line skipping

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo?ignorewseol=1'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 4 (intra whitespace on line 0)",
        "line": "line  0\n",
        "lineno": 1,
        "node": "08adbe269f24cf22d975eadeec16790c5b22f558",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 2 (leading whitespace on line 2)",
        "line": "    line 2\n",
        "lineno": 5,
        "node": "6bdb694e7b8cebb68d5b6b27b4bcc2a49d62c602",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 0",
        "line": "line 3    \n",
        "lineno": 6,
        "node": "b9c578134d72b3a9d26afde8ddd76c0a93c5adbc",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 4
      }
    ],
    "author": "test",
    "children": [],
    "date": [
      0.0,
      0
    ],
    "desc": "commit 6 (add another blank line between line 0 and 1)",
    "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
    "parents": [
      "400ef1d404706cfb48afd2b78ce6addf641ced25"
    ],
    "permissions": ""
  }

ignoreblanklines=1 query string enables whitespace blank line skipping

  $ get-with-headers.py --json $LOCALIP:$HGPORT 'json-annotate/9d1b2c7db017/foo?ignoreblanklines=1'
  200 Script output follows
  
  {
    "abspath": "foo",
    "annotate": [
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 4 (intra whitespace on line 0)",
        "line": "line  0\n",
        "lineno": 1,
        "node": "08adbe269f24cf22d975eadeec16790c5b22f558",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 1
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 5 (add blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 2,
        "node": "400ef1d404706cfb48afd2b78ce6addf641ced25",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 6 (add another blank line between line 0 and 1)",
        "line": "\n",
        "lineno": 3,
        "node": "9d1b2c7db0175870a950f8c48c9c4ead1058f2c5",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 3
      },
      {
        "abspath": "foo",
        "author": "test",
        "desc": "commit 1",
        "line": "line 1 modified by 1\n",
        "lineno": 4,
        "node": "23e1e37387dcfca4c0ed0cc568d1e4b9bfed241a",
        "revdate": [
          0.0,
          0
        ],
        "targetline": 2
      },
      {
        "abspath": "foo",
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        "desc": "commit 3 (trailing whitespace on line 3)",
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    "author": "test",
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    "desc": "commit 6 (add another blank line between line 0 and 1)",
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    "parents": [
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