[openwrt/openwrt] tools/automake: do not delete Makefile in clean targets

[LEDE Commits]

robimarko pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/9ea963e471d642c94159ab484f84b88ee3844201

commit 9ea963e471d642c94159ab484f84b88ee3844201
Author: Michael Pratt <mcpratt at pm.me>
AuthorDate: Fri Oct 4 01:25:13 2024 -0400

    tools/automake: do not delete Makefile in clean targets
    
    For the building of some packages, it is sometimes helpful
    to completely clean the packaged release copy of the source,
    however this usually both requires and deletes the Makefile,
    causing the need to run the configure stage twice.
    
    Not deleting the Makefile allows compilation to continue directly
    after cleaning pre-generated files in the package distribution.
    
    Signed-off-by: Michael Pratt <mcpratt at pm.me>
    Link: https://github.com/openwrt/openwrt/pull/16522
    Signed-off-by: Robert Marko <robimarko at gmail.com>
---
 tools/automake/patches/999-clean-am.patch | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tools/automake/patches/999-clean-am.patch b/tools/automake/patches/999-clean-am.patch
new file mode 100644
index 0000000000..87a0d6f3f6
--- /dev/null
+++ b/tools/automake/patches/999-clean-am.patch
@@ -0,0 +1,20 @@
+--- a/lib/am/clean.am
++++ b/lib/am/clean.am
+@@ -39,7 +39,7 @@ distclean-generic:
+ ## If you change distclean here, you probably also want to change
+ ## maintainer-clean below.
+ distclean:
+-	-rm -f %MAKEFILE%
++	-touch %MAKEFILE%
+ 
+ maintainer-clean-am: maintainer-clean-generic distclean-am
+ maintainer-clean-generic:
+@@ -51,7 +51,7 @@ maintainer-clean-generic:
+ 
+ ## See comment for distclean.
+ maintainer-clean:
+-	-rm -f %MAKEFILE%
++	-touch %MAKEFILE%
+ 
+ .PHONY: clean mostlyclean distclean maintainer-clean \
+ clean-generic mostlyclean-generic distclean-generic maintainer-clean-generic