Thread: best way to apply and work on the patches of the pg community

mahendrakar s <mahendrakarforpg@gmail.com> writes:
> I would like to work on a patch published on hackers community( patch is
> from June, 2021). I cloned postgres code and tried to  apply the patch and
> got errors.

> *patch -p1 < ../0001-auth-generalize-SASL-mechanisms.patch*
> patching file src/backend/libpq/auth-scram.c
> Hunk #1 FAILED at 101.
> Hunk #2 FAILED at 170.
> Hunk #3 FAILED at 199.
> Hunk #4 FAILED at 215.
> Hunk #5 FAILED at 325.

> Can you please let me know what is the recommended way to apply the patches
> for me to begin the work?

"patch -p1" is the way that usually works the best for me.  My guess
here is that the patch in question is out of date and will need manual
adjustment to apply to HEAD.  There have been some pretty significant
changes in that code in the last year, eg 9fd85570d.

Sometimes --ignore-whitespace helps, but I doubt that's the main
problem in this case.

            regards, tom lane

On 2022-Jul-15, mahendrakar s wrote:

> I would like to work on a patch published on hackers community( patch is
> from June, 2021). I cloned postgres code and tried to  apply the patch and
> got errors.
> 
> *patch -p1 < ../0001-auth-generalize-SASL-mechanisms.patch*
> patching file src/backend/libpq/auth-scram.c
> Hunk #1 FAILED at 101.

I would suggest to do a "git checkout" to a point in the tree near where
the patch was posted, then do "patch -p1" or "git apply" or "git am",
which is likely to work without conflict; then commit.  Then you can
merge to the tip of whatever branch it is, and you will get the
conflicts then.  It may be simpler to fix the conflicts there (with
git's help).

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
"En las profundidades de nuestro inconsciente hay una obsesiva necesidad
de un universo lógico y coherente. Pero el universo real se halla siempre
un paso más allá de la lógica" (Irulan)