Merge branch 'np/maint-limit-delta-cache' into maint

* np/maint-limit-delta-cache:
don't let the delta cache grow unbounded in 'git repack'

diff --combined Documentation/config.txt
index e94a8ab746293f47046babe4ed48201e8016f0ee,7791c32bc3461d7fcc73001165492b84c0997f06..2632c5149e380dd9d07b38803614b42db99f2658
--- 1/Documentation/config.txt
--- 2/Documentation/config.txt
+++ b/Documentation/config.txt
@@@ -605,7 -605,7 +605,7 @@@ color.interactive.<slot>:
        Use customized color for 'git-add --interactive'
        output. `<slot>` may be `prompt`, `header`, `help` or `error`, for
        four distinct types of normal output from interactive
 -      programs.  The values of these variables may be specified as
 +      commands.  The values of these variables may be specified as
        in color.branch.<slot>.
  
  color.pager::
@@@ -1113,7 -1113,7 +1113,7 @@@ instaweb.port:
        linkgit:git-instaweb[1].
  
  interactive.singlekey::
 -      In interactive programs, allow the user to provide one-letter
 +      In interactive commands, allow the user to provide one-letter
        input with a single key (i.e., without hitting enter).
        Currently this is used only by the `\--patch` mode of
        linkgit:git-add[1].  Note that this setting is silently
@@@ -1218,12 -1218,20 +1218,20 @@@ pack.compression:
  
  pack.deltaCacheSize::
        The maximum memory in bytes used for caching deltas in
-       linkgit:git-pack-objects[1].
-       A value of 0 means no limit. Defaults to 0.
+       linkgit:git-pack-objects[1] before writing them out to a pack.
+       This cache is used to speed up the writing object phase by not
+       having to recompute the final delta result once the best match
+       for all objects is found.  Repacking large repositories on machines
+       which are tight with memory might be badly impacted by this though,
+       especially if this cache pushes the system into swapping.
+       A value of 0 means no limit. The smallest size of 1 byte may be
+       used to virtually disable this cache. Defaults to 256 MiB.
  
  pack.deltaCacheLimit::
        The maximum size of a delta, that is cached in
-       linkgit:git-pack-objects[1]. Defaults to 1000.
+       linkgit:git-pack-objects[1]. This cache is used to speed up the
+       writing object phase by not having to recompute the final delta
+       result once the best match for all objects is found. Defaults to 1000.
  
  pack.threads::
        Specifies the number of threads to spawn when searching for best