Inline::C: Don't assume we can modify inplace and return the input buffer back to Perl.HEADmaster

1 files changed, 9 insertions, 7 deletions

diff --git a/mkindex.pl b/mkindex.pl
index 97fdf93..ed75907 100755
--- a/mkindex.pl
+++ b/mkindex.pl
@@ -498,7 +498,6 @@ sub expand_rgba {
         my $src_data = $src_band->ReadRaster(0, $y, $xSize, 1);
 
         for (my $b = 0; $b < $dst_nb; $b++) {
-            local $_ = $src_data;
             # We use an inlined C function to speed up things a bit.
             # Essentially what we're doing is a splice through the
             # lookup table.
@@ -507,8 +506,8 @@ sub expand_rgba {
             # than our C code, can be obtained using transliteration:
             #   my $src_str = join '', map chr, (0 .. $src_nc-1);
             #   eval "tr/\Q$src_str\E/\Q$lookup->[$b]\E/";
-            &subst ( $_, $lookup->[$b], $xSize );
-            $dst_ds->Band(1+$b)->WriteRaster(0, $y, $xSize, 1, $_);
+            my $dst_data = &subst( $src_data, $lookup->[$b], $xSize );
+            $dst_ds->Band(1+$b)->WriteRaster(0, $y, $xSize, 1, $dst_data);
         }
 
         &{$config{progress}}( (1+$y) / $ySize ) if $config{progress};
@@ -687,8 +686,11 @@ __END__
 
 __C__
 
-void subst (unsigned char *data, unsigned char *lookup, int length) {
-    int i;
-    for (i = 0; i < length; i++)
-        data[i] = lookup[ data[i] ];
+SV *subst(unsigned char *data, unsigned char *lookup, int length) {
+    char *out = malloc(length * sizeof(unsigned char));
+    for (int i = 0; i < length; i++)
+        out[i] = lookup[ data[i] ];
+    SV* ret = newSVpvn(out, length);
+    free(out);
+    return(ret);
 }