From 6a1dacb6b6c4e33ceed942d4b7c2724e6e6b713c Mon Sep 17 00:00:00 2001
From: Dongjoon Hyun <dongjoon@apache.org>
Date: Tue, 14 Sep 2021 16:26:50 -0700
Subject: [PATCH] [SPARK-36712][BUILD][FOLLOWUP] Improve the regex to avoid
 breaking pom.xml

### What changes were proposed in this pull request?

This PR aims to fix the regex to avoid breaking `pom.xml`.

### Why are the changes needed?

**BEFORE**
```
$ dev/change-scala-version.sh 2.12
$ git diff | head -n10
diff --git a/core/pom.xml b/core/pom.xml
index dbde22f2bf..6ed368353b 100644
--- a/core/pom.xml
+++ b/core/pom.xml
 -35,7 +35,7
   </properties>

   <dependencies>
-    <!--<!--
```

**AFTER**
Since the default Scala version is `2.12`, the following `no-op` is the correct behavior which is consistent with the previous behavior.
```
$ dev/change-scala-version.sh 2.12
$ git diff
```

### Does this PR introduce _any_ user-facing change?

No. This is a dev only change.

### How was this patch tested?

Manually.

Closes #33996 from dongjoon-hyun/SPARK-36712.

Authored-by: Dongjoon Hyun <dongjoon@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
(cherry picked from commit d730ef24fee49b32d9289fd203cbc7eb3b715017)
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
---
 dev/change-scala-version.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dev/change-scala-version.sh b/dev/change-scala-version.sh
index e17a2249cc..102c438a99 100755
--- a/dev/change-scala-version.sh
+++ b/dev/change-scala-version.sh
@@ -60,7 +60,7 @@ for f in $(find "$BASEDIR" -name 'pom.xml' -not -path '*target*'); do
   sed_i 's/\(artifactId.*\)_'$FROM_VERSION'/\1_'$TO_VERSION'/g' $f
   sed_i 's/^\([[:space:]]*<!-- #if scala-'$TO_VERSION' -->\)<!--/\1/' $f
   sed_i 's/^\([[:space:]]*\)-->\(<!-- #endif scala-'$TO_VERSION' -->\)/\1\2/' $f
-  sed_i 's/^\([[:space:]]*<!-- #if scala-'$FROM_VERSION' -->\)/\1<!--/' $f
+  sed_i 's/^\([[:space:]]*<!-- #if scala-'$FROM_VERSION' -->\)$/\1<!--/' $f
   sed_i 's/^\([[:space:]]*\)\(<!-- #endif scala-'$FROM_VERSION' -->\)/\1-->\2/' $f
 done