revision.c: introduce --min-parents and --max-parents options

diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt
index ef86763948dbebefd810032bfca1e757d2016920..4415e636352ea88f34a798b6c29dc5e34d60d868 100644 (file)
--- a/Documentation/git-fast-import.txt
+++ b/Documentation/git-fast-import.txt
@@ -92,6 +92,11 @@ OPTIONS
        --(no-)-relative-marks= with the --(import|export)-marks=
        options.
 
+--cat-blob-fd=<fd>::
+       Specify the file descriptor that will be written to
+       when the `cat-blob` command is encountered in the stream.
+       The default behaviour is to write to `stdout`.
+
 --export-pack-edges=<file>::
        After creating a packfile, print a line of data to
        <file> listing the filename of the packfile and the last
@@ -320,6 +325,11 @@ and control the current import process.  More detailed discussion
        standard output.  This command is optional and is not needed
        to perform an import.
 
+`cat-blob`::
+       Causes fast-import to print a blob in 'cat-file --batch'
+       format to the file descriptor set with `--cat-blob-fd` or
+       `stdout` if unspecified.
+
 `feature`::
        Require that fast-import supports the specified feature, or
        abort if it does not.
@@ -524,9 +534,6 @@ start with double quote (`"`).
 If an `LF` or double quote must be encoded into `<path>` shell-style
 quoting should be used, e.g. `"path/with\n and \" in it"`.
 
-Additionally, in `040000` mode, `<path>` may also be an empty string
-(`""`) to specify the root of the tree.
-
 The value of `<path>` must be in canonical form. That is it must not:
 
 * contain an empty directory component (e.g. `foo//bar` is invalid),
@@ -535,6 +542,8 @@ The value of `<path>` must be in canonical form. That is it must not:
 * contain the special component `.` or `..` (e.g. `foo/./bar` and
   `foo/../bar` are invalid).
 
+The root of the tree can be represented by an empty string as `<path>`.
+
 It is recommended that `<path>` always be encoded using UTF-8.
 
 `filedelete`
@@ -879,6 +888,33 @@ Placing a `progress` command immediately after a `checkpoint` will
 inform the reader when the `checkpoint` has been completed and it
 can safely access the refs that fast-import updated.
 
+`cat-blob`
+~~~~~~~~~~
+Causes fast-import to print a blob to a file descriptor previously
+arranged with the `--cat-blob-fd` argument.  The command otherwise
+has no impact on the current import; its main purpose is to
+retrieve blobs that may be in fast-import's memory but not
+accessible from the target repository.
+
+....
+       'cat-blob' SP <dataref> LF
+....
+
+The `<dataref>` can be either a mark reference (`:<idnum>`)
+set previously or a full 40-byte SHA-1 of a Git blob, preexisting or
+ready to be written.
+
+Output uses the same format as `git cat-file --batch`:
+
+====
+       <sha1> SP 'blob' SP <size> LF
+       <contents> LF
+====
+
+This command can be used anywhere in the stream that comments are
+accepted.  In particular, the `cat-blob` command can be used in the
+middle of a commit but not in the middle of a `data` command.
+
 `feature`
 ~~~~~~~~~
 Require that fast-import supports the specified feature, or abort if
@@ -905,6 +941,13 @@ import-marks::
        second, an --import-marks= command-line option overrides
        any "feature import-marks" command in the stream.
 
+cat-blob::
+       Ignored.  Versions of fast-import not supporting the
+       "cat-blob" command will exit with a message indicating so.
+       This lets the import error out early with a clear message,
+       rather than wasting time on the early part of an import
+       before the unsupported command is detected.
+
 `option`
 ~~~~~~~~
 Processes the specified option so that git fast-import behaves in a
@@ -930,6 +973,7 @@ not be passed as option:
 * date-format
 * import-marks
 * export-marks
+* cat-blob-fd
 * force
 
 Crash Reports
@@ -1230,6 +1274,13 @@ and lazy loading of subtrees, allows fast-import to efficiently import
 projects with 2,000+ branches and 45,114+ files in a very limited
 memory footprint (less than 2.7 MiB per active branch).
 
+Signals
+-------
+Sending *SIGUSR1* to the 'git fast-import' process ends the current
+packfile early, simulating a `checkpoint` command.  The impatient
+operator can use this facility to peek at the objects and refs from an
+import in progress, at the cost of some added running time and worse
+compression.
 
 Author
 ------