Allow to opt-out from shebang mangling for specific paths/shebangs

Introduces __brp_mangle_shebangs_exclude_from and __brp_mangle_shebangs_exclude

 * the first allows to explude specific paths from the mangling
 * the second allows to exlude specific shebangs

Both are used with `grep -E`. Similar escaping rules as in [1] apply.

[1] https://fedoraproject.org/wiki/Packaging:AutoProvidesAndRequiresFiltering

brp-mangle-shebangs

@@ -5,6 +5,9 @@ if [ -z "$RPM_BUILD_ROOT" -o "$RPM_BUILD_ROOT" = "/" ]; then
   exit 0
 fi
 
+exclude_files="${1:-}"
+exclude_shebangs="${2:-}"
+
 cd "$RPM_BUILD_ROOT"
 
 trim() {
@@ -14,10 +17,21 @@ trim() {
 fail=0
 for f in $(find -executable -type f | xargs --no-run-if-empty file -N --mime-type | grep -Po "^\K.+(?=: text/)"); do
 
+  # Remove the dot
+  path="${f#.}"
+
+  if [ -n "$exclude_files" ]; then
+    echo "$path" | grep -q -E "$exclude_files" && continue
+  fi
+
   ts=$(stat -c %y "$f")
 
   read orig_shebang < "$f" || :
   shebang=$(trim $(echo "$orig_shebang" | grep -Po "#!\K.*" || echo))
+  if [ -n "$exclude_shebangs" ]; then
+    echo "$shebang" | grep -q -E "$exclude_shebangs" && continue
+  fi
+
   if [ -z "$shebang" ]; then
     echo >&2 "*** WARNING: $f is executable but has empty or no shebang, removing executable bit"
     chmod -x "$f"
@@ -44,10 +58,10 @@ for f in $(find -executable -type f | xargs --no-run-if-empty file -N --mime-typ
 
   if [ "$shebang" != "$py_shebang" ]; then
     sed -i -e "1c #!$py_shebang" "$f"
-    echo >&2 "*** WARNING: mangling shebang in $f from $orig_shebang to #!$py_shebang. This will become an ERROR, fix it manually!"
+    echo >&2 "*** WARNING: mangling shebang in $path from $orig_shebang to #!$py_shebang. This will become an ERROR, fix it manually!"
   elif [ "#!$shebang" != "$orig_shebang" ]; then
     sed -i -e "1c #!$shebang" "$f"
-    echo "mangling shebang in $f from $orig_shebang to #!$shebang"
+    echo "mangling shebang in $path from $orig_shebang to #!$shebang"
   fi
 
   touch -d "$ts" "$f"

macros

@@ -143,7 +143,7 @@
 %__brp_strip_static_archive /usr/lib/rpm/brp-strip-static-archive %{__strip}
 %__brp_python_bytecompile /usr/lib/rpm/brp-python-bytecompile %{__python} %{?_python_bytecompile_errors_terminate_build}
 %__brp_python_hardlink /usr/lib/rpm/brp-python-hardlink
-%__brp_mangle_shebangs /usr/lib/rpm/redhat/brp-mangle-shebangs
+%__brp_mangle_shebangs /usr/lib/rpm/redhat/brp-mangle-shebangs "%{?__brp_mangle_shebangs_exclude_from}" "%{?__brp_mangle_shebangs_exclude}"
 
 %__os_install_post    \
     %{?__brp_ldconfig} \

redhat-rpm-config.spec

@@ -6,7 +6,7 @@
 
 Summary: Red Hat specific rpm configuration files
 Name: redhat-rpm-config
-Version: 96
+Version: 97
 Release: 1%{?dist}
 # No version specified.
 License: GPL+
@@ -183,6 +183,9 @@ install -p -m 755 -t %{buildroot}%{_rpmconfigdir} kmod.prov
 %{_rpmconfigdir}/macros.d/macros.kmp
 
 %changelog
+* Wed Feb 14 2018 Miro Hrončok <mhroncok@redhat.com> - 97-1
+- Allow to opt-out from shebang mangling for specific paths/shebangs
+
 * Thu Feb 08 2018 Igor Gnatenko <ignatenkobrain@fedoraproject.org> - 96-1
 - Simplify/Fix check for shebang starting with "/"