[PATCH] checkpatch: Emit an error when there's a diff in a changelog

Joe Perches
2015-06-12T17:51:52Z

People often put diff snippets in changelogs. This causes problems
when one tries to apply a file containing both the changelog and the
diff because patch(1) tries to apply the diff which it found in the
changelog.

Warn once when what seems to be a diff snippet in the changelog exists.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Joe Perches <joe@perches.com>
---
scripts/checkpatch.pl | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 69c4716..86e4fb1 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -1954,6 +1954,7 @@ sub process {
my $in_header_lines = $file ? 0 : 1;
my $in_commit_log = 0; #Scanning lines before patch
my $commit_log_long_line = 0;
+ my $commit_log_has_diff = 0;
my $reported_maintainer_file = 0;
my $non_utf8_charset = 0;

@@ -2087,7 +2088,8 @@ sub process {
my $rawline = $rawlines[$linenr - 1];

#extract the line range in the file after the patch is applied
- if ($line=~/^\@\@ -\d+(?:,\d+)? \+(\d+)(,(\d+))? \@\@/) {
+ if (!$in_commit_log &&
+ $line =~ /^\@\@ -\d+(?:,\d+)? \+(\d+)(,(\d+))? \@\@/) {
$is_patch = 1;
$first_line = $linenr + 1;
$realline=$1-1;
@@ -2181,6 +2183,17 @@ sub process {

$cnt_lines++ if ($realcnt != 0);

+# Check if the commit log has what seems like a diff which can confuse patch
+ if ($in_commit_log && !$commit_log_has_diff &&
+ (($line =~ m@^\s+diff\b.*a/[\w/]+@ &&
+ $line =~ m@^\s+diff\b.*a/([\w/]+)\s+b/$1\b@) ||
+ $line =~ m@^\s*(?:\-\-\-\s+a/|\+\+\+\s+b/)@ ||
+ $line =~ m/^\s*\@\@ \-\d+,\d+ \+\d+,\d+ \@\@/)) {
+ ERROR("DIFF_IN_COMMIT_MSG",
+ "Avoid using diff content in the commit message - patch(1) might not work\n" . $herecurr);
+ $commit_log_has_diff = 1;
+ }
+
# Check for incorrect file permissions
if ($line =~ /^new (file )?mode.*[7531]\d{0,2}$/) {
my $permhere = $here . "FILE: $realfile\n";