Merge #12572: [script] lint-whitespace: find errors more easily

0fbed98 [script] lint-whitespace: improve print linenumber (Akio Nakamura)

Pull request description:

  Before this PR, the linenumber infomaition is output if trailing-space or tab code was found, but the output occurence is only per a file.
  This PR separates the output timing of file name and line number.
  As a result, users will find where they need to fix more easily.

  example:

  0) git diff
  ```
  diff --git a/dummy.txt b/dummy.txt
  index c0ce4d776..aebbdb88d 100644
  --- a/dummy.txt
  +++ b/dummy.txt
  @@ -1,2 +1,2 @@
  -1
  -2
  +1
  +       2
  @@ -8,2 +8,2 @@
  -8
  -9
  +       8
  +9
  ```

  1) before this PR - Is there "9 " in second line? It may lead to be misunderstood.
  ```
  This diff appears to have added new lines with trailing whitespace.
  The following changes were suspected:

  diff --git a/dummy.txt b/dummy.txt
  @@ -1,2 +1,2 @@
  +1
  +9
  ```

  2) after this PR
  ```
  This diff appears to have added new lines with trailing whitespace.
  The following changes were suspected:

  diff --git a/dummy.txt b/dummy.txt
  @@ -1,2 +1,2 @@
  +1
  @@ -8,2 +8,2 @@
  +9
  ```

Tree-SHA512: 2fd52e3c982786f86cfe10aa2578589bc9c502bcad9b85111467840d726143330c23968cde5483ee0f563893c8381044b80e8c22a7c8eca56fc73c548b9a9496

Author: MarcoFalke

contrib/devtools/lint-whitespace.sh

@@ -51,21 +51,26 @@ if showdiff | grep -E -q '^\+.*\s+$'; then
   echo "The following changes were suspected:"
   FILENAME=""
   SEEN=0
+  SEENLN=0
   while read -r line; do
     if [[ "$line" =~ ^diff ]]; then
       FILENAME="$line"
       SEEN=0
     elif [[ "$line" =~ ^@@ ]]; then
       LINENUMBER="$line"
+      SEENLN=0
     else
       if [ "$SEEN" -eq 0 ]; then
         # The first time a file is seen with trailing whitespace, we print the
         # filename (preceded by a newline).
         echo
         echo "$FILENAME"
-        echo "$LINENUMBER"
         SEEN=1
       fi
+      if [ "$SEENLN" -eq 0 ]; then
+        echo "$LINENUMBER"
+        SEENLN=1
+      fi
       echo "$line"
     fi
   done < <(showdiff | grep -E '^(diff --git |@@|\+.*\s+$)')
@@ -78,21 +83,26 @@ if showcodediff | perl -nle '$MATCH++ if m{^\+.*\t}; END{exit 1 unless $MATCH>0}
   echo "The following changes were suspected:"
   FILENAME=""
   SEEN=0
+  SEENLN=0
   while read -r line; do
     if [[ "$line" =~ ^diff ]]; then
       FILENAME="$line"
       SEEN=0
     elif [[ "$line" =~ ^@@ ]]; then
       LINENUMBER="$line"
+      SEENLN=0
     else
       if [ "$SEEN" -eq 0 ]; then
         # The first time a file is seen with a tab character, we print the
         # filename (preceded by a newline).
         echo
         echo "$FILENAME"
-        echo "$LINENUMBER"
         SEEN=1
       fi
+      if [ "$SEENLN" -eq 0 ]; then
+        echo "$LINENUMBER"
+        SEENLN=1
+      fi
       echo "$line"
     fi
   done < <(showcodediff | perl -nle 'print if m{^(diff --git |@@|\+.*\t)}')