app-shells/bash: optimise SRC_URI generation

Thanks to radhermit's new pkgcraft tooling. Also, thanks to ztrawhcse for suggestions.

Before:
```
app-shells/bash-5.2_p15-r3::.: 61.224122ms
app-shells/bash-5.1_p16-r4::.: 65.001125ms
app-shells/bash-5.1_p16-r5::.: 65.480029ms
```

After:
```
app-shells/bash-5.2_p15-r3::/home/sam/g/: 10.449073ms
app-shells/bash-5.1_p16-r4::/home/sam/g/: 10.505063ms
app-shells/bash-5.1_p16-r5::/home/sam/g/: 10.523583ms
```

This also gets us to approximately the same speed (almost within rounding
error) of pre-d3c19b7974aeb4ac2a1351a019e80625b4111c4b (where we removed eval
usage).

Signed-off-by: Sam James <sam@gentoo.org>

1 files changed, 14 insertions, 7 deletions

diff --git a/app-shells/bash/bash-9999.ebuild b/app-shells/bash/bash-9999.ebuild
index 82dfe5fb1c66..af8066bbfd29 100644
--- a/app-shells/bash/bash-9999.ebuild
+++ b/app-shells/bash/bash-9999.ebuild
@@ -53,17 +53,24 @@ elif is_release ; then
 		patch_url=
 		my_patch_index=
 
+		upstream_url_base="mirror://gnu/bash"
+		mirror_url_base="ftp://ftp.cwru.edu/pub/bash"
+
 		for ((my_patch_index=1; my_patch_index <= ${PLEVEL} ; my_patch_index++)) ; do
-			for url in mirror://gnu/${pn} ftp://ftp.cwru.edu/pub/bash ; do
-				patch_url=$(printf "${url}/${PN}-$(ver_cut 1-2)-patches/${my_p}-%03d" ${my_patch_index})
-				SRC_URI+=" ${patch_url}"
-				SRC_URI+=" verify-sig? ( ${patch_url}.sig )"
-			done
+			printf -v mangled_patch_ver ${my_p}-%03d ${my_patch_index}
+			patch_url="${upstream_url_base}/${MY_P}-patches/${mangled_patch_ver}"
+
+			SRC_URI+=" ${patch_url}"
+			SRC_URI+=" verify-sig? ( ${patch_url}.sig )"
+
+			# Add in the mirror URL too.
+			SRC_URI+=" ${patch_url/${upstream_url_base}/${mirror_url_base}}"
+			SRC_URI+=" verify-sig? ( ${patch_url/${upstream_url_base}/${mirror_url_base}} )"
 
-			MY_PATCHES+=( "${DISTDIR}"/$(printf ${my_p}-%03d ${my_patch_index}) )
+			MY_PATCHES+=( "${DISTDIR}"/${mangled_patch_ver} )
 		done
 
-		unset my_pn patch_url my_patch_index
+		unset my_p patch_url my_patch_index upstream_url_base mirror_url_base
 	fi
 else
 	SRC_URI="mirror://gnu/${PN}/${MY_P}.tar.gz ftp://ftp.cwru.edu/pub/bash/${MY_P}.tar.gz"