builder: fix get_sources — quote PERCONAFT/TOKUBACKUP tests, pick cmake3 fallback

Two bugs in get_sources() on the release-9.7.0-1-1 Jenkins build:

1. Lines 223 / 226: `[ ${PERCONAFT_REPO} = 0 ]` / `[ ${TOKUBACKUP_REPO} = 0 ]`

   When PERCONAFT_REPO / TOKUBACKUP_REPO are empty or unset (the
   normal case for non-TokuDB builds) the unquoted substitution
   collapses the test to literal `[ = 0 ]` and bash reports:

       ./ps_builder.sh: line 223: [: =: unary operator expected
       ./ps_builder.sh: line 226: [: =: unary operator expected

   Quote both sides + add `:-` default so the test evaluates as
   `[ "" = "0" ]` (false) rather than producing a syntax error.

2. Line 269: `cmake . -DWITH_SSL=system ...`

   PS 9.x requires CMake >= 3.17.5 (top-level CMakeLists.txt:112).
   Some release build agents still ship CMake 3.16.3 as the default
   `cmake`, so the configure step aborts:

       CMake Error at CMakeLists.txt:112 (CMAKE_MINIMUM_REQUIRED):
         CMake 3.17.5 or higher is required.  You are running version 3.16.3

   With cmake failing, no Makefile is generated, `make dist` then
   reports `No rule to make target 'dist'`, and EXPORTED_TAR / PSDIR
   end up empty. Every later step cascades into corruption:
   `tar xzf` with no arg, rsync targets resolve to absolute `/storage/...`
   paths, `cd ${PSDIR}` becomes `cd` (home dir), and the subsequent
   sed of `build-ps/debian/rules` fails with "No such file".

   On hosts that have both `cmake` (old) and `cmake3` (EPEL /
   backports alternative), prefer `cmake3` when the default `cmake`
   is older than 3.17.5. Same pattern build-ps/pxc_builder.sh
   already uses for PXC on EL7.

   This does NOT help hosts where neither `cmake` nor `cmake3` is
   >= 3.17.5 — those need either a base-image cmake bump or a
   cmake install in install_deps. Note: the make dist step legitimately
   needs cmake to copy bison-generated sql_yacc.{h,cc} /
   sql_hints.yy.{h,cc} into the tarball and to autoreconf UDF/, so
   replacing it with plain `git archive` would silently drop those
   pre-generated files. Keeping the cmake+make-dist path and just
   choosing a sufficient cmake binary is the right answer.

Author: EvgeniyPatlan

build-ps/percona-server-9.0_builder.sh

@@ -220,10 +220,12 @@ get_sources(){
     git submodule update
     rm -rf storage/tokudb/PerconaFT
     rm -rf plugin/tokudb-backup-plugin/Percona-TokuBackup
-    if [ ${PERCONAFT_REPO} = 0 ]; then
+    # Quote both sides + provide :- default so an empty / unset variable
+    # does not collapse to literal `[ = 0 ]` and trip "unary operator expected".
+    if [ "${PERCONAFT_REPO:-}" = "0" ]; then
         PERCONAFT_REPO=''
     fi
-    if [ ${TOKUBACKUP_REPO} = 0 ]; then
+    if [ "${TOKUBACKUP_REPO:-}" = "0" ]; then
         TOKUBACKUP_REPO=''
     fi
 
@@ -266,7 +268,24 @@ get_sources(){
     #
     git submodule update
     #
-    cmake .  -DWITH_SSL=system -DFORCE_INSOURCE_BUILD=1 -DWITH_ZLIB=bundled -DWITH_CURL=bundled
+    # `make dist` is implemented as a cmake-driven custom target in
+    # sql/CMakeLists.txt → cmake/make_dist.cmake.in, which not only
+    # git-archives HEAD but also copies bison-generated parser files
+    # (sql_yacc.{h,cc}, sql_hints.yy.{h,cc}) into the tarball and
+    # autoreconfs the UDF subtree. cmake configure must succeed first
+    # for this target to exist, and PS 9.x requires cmake >= 3.17.5.
+    #
+    # On hosts where the default `cmake` is older than 3.17.5 (some
+    # build agents still ship cmake 3.16.3), fall back to `cmake3`
+    # which is the EPEL/backports alternative providing a newer
+    # version. Same pattern PXC uses in build-ps/pxc_builder.sh.
+    CMAKE_BIN="cmake"
+    if ! cmake --version 2>/dev/null | head -1 | awk '{print $3}' | grep -qE "^([4-9]|3\.(1[7-9]|[2-9][0-9]))"; then
+        if command -v cmake3 >/dev/null 2>&1; then
+            CMAKE_BIN="cmake3"
+        fi
+    fi
+    "${CMAKE_BIN}" .  -DWITH_SSL=system -DFORCE_INSOURCE_BUILD=1 -DWITH_ZLIB=bundled -DWITH_CURL=bundled
     make dist
     #
     EXPORTED_TAR=$(basename $(find . -type f -name percona-server*.tar.gz | sort | tail -n 1))