contacts: validate hunk length earlier

sunshineco · gitster · commit 9ae9ca1f95cc · 2013-08-13T09:08:58.000-07:00
Rather than calling get_blame() with a zero-length hunk only to have it
rejected immediately, perform hunk-length validation earlier in order to
avoid calling get_blame() unnecessarily.

This is a preparatory step to simplify later patches which reduce the
number of git-blame invocations by collecting together all lines to
blame within a single file at a particular revision. By validating the
blame range early, the subsequent patch can more easily avoid adding
empty ranges at collection time.

Signed-off-by: Eric Sunshine &lt;sunshine@sunshineco.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/contrib/contacts/git-contacts b/contrib/contacts/git-contacts
@@ -60,8 +60,6 @@ sub import_commits {
 
 sub get_blame {
 	my ($commits, $source, $start, $len, $from) = @_;
-	$len = 1 unless defined($len);
-	return if $len == 0;
 	open my $f, '-|',
 		qw(git blame --porcelain -C), '-L', "$start,+$len",
 		'--since', $since, "$from^", '--', $source or die;
@@ -90,7 +88,8 @@ sub scan_patches {
 		} elsif (/^--- /) {
 			die "Cannot parse hunk source: $_\n";
 		} elsif (/^@@ -(\d+)(?:,(\d+))?/ && $source) {
-			get_blame($commits, $source, $1, $2, $id);
+			my $len = defined($2) ? $2 : 1;
+			get_blame($commits, $source, $1, $len, $id) if $len;
 		}
 	}
 }

Original file line number	Diff line number	Diff line change
`@@ -60,8 +60,6 @@ sub import_commits {`
`60`	`60`
`61`	`61`	`sub get_blame {`
`62`	`62`	`my ($commits, $source, $start, $len, $from) = @_;`
`63`		`- $len = 1 unless defined($len);`
`64`		`- return if $len == 0;`
`65`	`63`	`open my $f, '-\|',`
`66`	`64`	`qw(git blame --porcelain -C), '-L', "$start,+$len",`
`67`	`65`	`'--since', $since, "$from^", '--', $source or die;`
`@@ -90,7 +88,8 @@ sub scan_patches {`
`90`	`88`	`} elsif (/^--- /) {`
`91`	`89`	`die "Cannot parse hunk source: $_\n";`
`92`	`90`	`} elsif (/^@@ -(\d+)(?:,(\d+))?/ && $source) {`
`93`		`- get_blame($commits, $source, $1, $2, $id);`
	`91`	`+ my $len = defined($2) ? $2 : 1;`
	`92`	`+ get_blame($commits, $source, $1, $len, $id) if $len;`
`94`	`93`	`}`
`95`	`94`	`}`
`96`	`95`	`}`