Recognize other lines generated by sdiff

Author: prioux

bin/csdiff

@@ -72,6 +72,7 @@ my $CHANGED   = ON_BLUE;
 my $MISSINGNL = ON_MAGENTA;
 my $UNCHANGED = "";
 my $OMITTED   = MAGENTA;
+my $MESSAGE   = BLACK . ON_YELLOW; # lines generated by sdiff outside of diffs proper
 
 my $OFF       = RESET;
 
@@ -174,7 +175,13 @@ my @spec = ();
 for (my $n=0;$n<@out;$n++) {
     my $line = $out[$n];
     chomp $line;
-    my $spec = length($line) >= $spos ? substr($line,$spos,1) : " ";
+    my $spec = " ";
+    if ($line =~ /^diff |^Common subdirectories:|^Only in/) {
+      $spec = "m"; # means a message generated by sdiff
+      $line = $MESSAGE.$line.$OFF."\n";
+    } else {
+      $spec = length($line) >= $spos ? substr($line,$spos,1) : " ";
+    }
     if ($spec eq ">") {
         $line .= (" " x ($cols - length($line)));
         $line = $INSERT.$line.$OFF."\n";
@@ -187,9 +194,9 @@ for (my $n=0;$n<@out;$n++) {
     } elsif (($spec eq "/") || ($spec eq "\\")) {
         $line .= (" " x ($cols - length($line)));
         $line = $MISSINGNL.$line.$OFF."\n";
-    } else {
-        $line = $UNCHANGED.$line.$UNCHOFF."\n";
+    } elsif ($spec ne "m") {
         $spec = " ";
+        $line = $UNCHANGED.$line.$UNCHOFF."\n";
     }
     $out[$n]  = $line;
     $spec[$n] = $spec;
@@ -198,6 +205,7 @@ for (my $n=0;$n<@out;$n++) {
 my %SHOW_SPECS=();
 $FILTERS ||= "udamco"; # all
 $FILTERS .= "u" if defined($CONTEXT);
+$SHOW_SPECS{"m"}=1;                        # sdiff messages
 $SHOW_SPECS{" "}=1 if $FILTERS =~ /[us]/i; # unchanged/same
 $SHOW_SPECS{"<"}=1 if $FILTERS =~ /d/i;    # deleted
 $SHOW_SPECS{">"}=1 if $FILTERS =~ /a/i;    # added
@@ -210,7 +218,7 @@ if (defined($CONTEXT)) {
     my $prevend = -1;
     for (my $n=0;$n<@out;$n++) {
         my $spec = $spec[$n] || " ";
-        next if $spec eq " " || !$SHOW_SPECS{$spec};
+        next if $spec =~ /[m ]/ || !$SHOW_SPECS{$spec};
         my $start = $n - $CONTEXT; $start = 0 if $start < 0;
         $start = $prevend + 1 if $start <= $prevend;
         my $end   = $n;