merge(3p/git): Merge git subtree at v2.29.2

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

third_party/git/Documentation/git-bisect-lk2009.txt

@@ -158,7 +158,7 @@ Test suites are very nice. But when they are used alone, they are
 supposed to be used so that all the tests are checked after each
 commit. This means that they are not very efficient, because many
 tests are run for no interesting result, and they suffer from
-combinational explosion.
+combinatorial explosion.
 
 In fact the problem is that big software often has many different
 configuration options and that each test case should pass for each
@@ -473,7 +473,7 @@ Z-Z
 -------------
 
 2) starting from the "good" ends of the graph, associate to each
-commit the number of ancestors it has plus one
+   commit the number of ancestors it has plus one
 
 For example with the following graph where H is the "bad" commit and A
 and D are some parents of some "good" commits:
@@ -514,7 +514,7 @@ D---E
 -------------
 
 4) the best bisection point is the commit with the highest associated
-number
+   number
 
 So in the above example the best bisection point is commit C.
 
@@ -580,8 +580,8 @@ good or a bad commit does not give more or less information).
 
 Let's also suppose that we have a cleaned up graph like one after step
 1) in the bisection algorithm above. This means that we can measure
-the information we get in terms of number of commit we can remove from
-the graph..
+   the information we get in terms of number of commit we can remove
+   from the graph..
 
 And let's take a commit X in the graph.
 
@@ -689,18 +689,18 @@ roughly the following steps:
 6) sort the commit by decreasing associated value
 
 7) if the first commit has not been skipped, we can return it and stop
-here
+   here
 
 8) otherwise filter out all the skipped commits in the sorted list
 
 9) use a pseudo random number generator (PRNG) to generate a random
-number between 0 and 1
+   number between 0 and 1
 
 10) multiply this random number with its square root to bias it toward
-0
+    0
 
 11) multiply the result by the number of commits in the filtered list
-to get an index into this list
+    to get an index into this list
 
 12) return the commit at the computed index
 
@@ -1350,9 +1350,9 @@ References
 - [[[1]]] https://www.nist.gov/sites/default/files/documents/director/planning/report02-3.pdf['The Economic Impacts of Inadequate Infratructure for Software Testing'.  Nist Planning Report 02-3], see Executive Summary and Chapter 8.
 - [[[2]]] http://www.oracle.com/technetwork/java/codeconvtoc-136057.html['Code Conventions for the Java Programming Language'. Sun Microsystems.]
 - [[[3]]] https://en.wikipedia.org/wiki/Software_maintenance['Software maintenance'. Wikipedia.]
-- [[[4]]] https://public-inbox.org/git/7vps5xsbwp.fsf_-_@assigned-by-dhcp.cox.net/[Junio C Hamano. 'Automated bisect success story'.]
+- [[[4]]] https://lore.kernel.org/git/7vps5xsbwp.fsf_-_@assigned-by-dhcp.cox.net/[Junio C Hamano. 'Automated bisect success story'.]
 - [[[5]]] https://lwn.net/Articles/317154/[Christian Couder. 'Fully automated bisecting with "git bisect run"'. LWN.net.]
 - [[[6]]] https://lwn.net/Articles/277872/[Jonathan Corbet. 'Bisection divides users and developers'. LWN.net.]
-- [[[7]]] http://marc.info/?l=linux-kernel&m=119702753411680&w=2[Ingo Molnar. 'Re: BUG 2.6.23-rc3 can't see sd partitions on Alpha'. Linux-kernel mailing list.]
+- [[[7]]] https://lore.kernel.org/lkml/20071207113734.GA14598@elte.hu/[Ingo Molnar. 'Re: BUG 2.6.23-rc3 can't see sd partitions on Alpha'. Linux-kernel mailing list.]
 - [[[8]]] https://www.kernel.org/pub/software/scm/git/docs/git-bisect.html[Junio C Hamano and the git-list. 'git-bisect(1) Manual Page'. Linux Kernel Archives.]
 - [[[9]]] https://github.com/Ealdwulf/bbchop[Ealdwulf. 'bbchop'. GitHub.]