difftool: Check all return codes from compare()

diff --git a/git-difftool.perl b/git-difftool.perl
index 30574801be36d83cb77bed6423a16a5f634ace4b..92f4907bbc1ba4886a5cfcf59b760457a9191a1f 100755 (executable)
--- a/git-difftool.perl
+++ b/git-difftool.perl
@@ -370,7 +370,16 @@ sub dir_diff
        # external tool did not replace the original link with a file.
        for my $file (@worktree) {
                next if $symlinks && -l "$b/$file";
-               if (-f "$b/$file" && compare("$b/$file", "$workdir/$file")) {
+               next if ! -f "$b/$file";
+
+               my $diff = compare("$b/$file", "$workdir/$file");
+               if ($diff == 0) {
+                       next;
+               } elsif ($diff == -1) {
+                       my $errmsg = "warning: Could not compare ";
+                       $errmsg += "'$b/$file' with '$workdir/$file'\n";
+                       warn $errmsg;
+               } elsif ($diff == 1) {
                        copy("$b/$file", "$workdir/$file") or die $!;
                        my $mode = stat("$b/$file")->mode;
                        chmod($mode, "$workdir/$file") or die $!;