fix(_mock,rpm): avoid icase flag s/reg/rep/i of GNU sed

Flag i for the case-insensitive matching is a GNU extension and thus
should be avoided.

The mock completion contains s/.../.../i while the rpm completion also
contains a similar code but without flag i.  The related sed code in
the rpm completion was introduced in commit 14c9f5b (2009-05-23),
and that in the mock completion was introduced in commit 508a88e
(2009-05-31).  The former did not have flag i while the latter had
flag i from the beginning.

In this patch, we assume the case-insensitive flag was intended for
both cases and update the regular expression so that it matches in a
case-insensitive manner also in the rpm completion.

Author: akinomyoga

completions/_mock

@@ -40,12 +40,15 @@ _comp_cmd_mock()
             return
             ;;
         --target)
+            # Case-insensitive BRE to match "compatible archs"
+            local regex_header='[cC][oO][mM][pP][aA][tT][iI][bB][lL][eE][[:space:]]\{1,\}[aA][rR][cC][hH][sS]'
+
             # Yep, compatible archs, not compatible build archs
             # (e.g. ix86 chroot builds in x86_64 mock host)
             # This would actually depend on what the target root
             # can be used to build for...
             _comp_compgen_split -- "$(command rpm --showrc | command sed -ne \
-                's/^[[:space:]]*compatible[[:space:]]\{1,\}archs[[:space:]]*:[[:space:]]*\(.*\)/\1/i p')"
+                "s/^[[:space:]]*${regex_header}[[:space:]]*:[[:space:]]*\(.*\)/\1/p")"
             return
             ;;
         --enable-plugin | --disable-plugin)

completions/rpm

@@ -44,8 +44,10 @@ _comp_cmd_rpm__macros()
 # shellcheck disable=SC2120
 _comp_cmd_rpm__buildarchs()
 {
+    # Case-insensitive BRE to match "compatible build archs"
+    local regex_header='[cC][oO][mM][pP][aA][tT][iI][bB][lL][eE][[:space:]]\{1,\}[bB][uU][iI][lL][dD][[:space:]]\{1,\}[aA][rR][cC][hH][sS]'
     _comp_compgen_split -- "$("${1:-rpm}" --showrc | command sed -ne \
-        's/^[[:space:]]*compatible[[:space:]]\{1,\}build[[:space:]]\{1,\}archs[[:space:]]*:[[:space:]]*\(.*\)/\1/ p')"
+        "s/^[[:space:]]*${regex_header}[[:space:]]*:[[:space:]]*\(.*\)/\1/p")"
 }
 
 # shellcheck disable=SC2120