[PATCH 5/5] usp10: Avoid special handling if the substitution count is 0 in GSUB_apply_ChainContextSubst().

[Aric Stewart]

Signed-off-by: Aric Stewart <aric at codeweavers.com>

On 4/6/17 5:03 AM, Henri Verbeet wrote:
> Signed-off-by: Henri Verbeet <hverbeet at codeweavers.com>
> ---
>  dlls/usp10/opentype.c | 62 +++++++++++++++++++++------------------------------
>  1 file changed, 26 insertions(+), 36 deletions(-)
> 
> diff --git a/dlls/usp10/opentype.c b/dlls/usp10/opentype.c
> index 81a5180..a3346ef 100644
> --- a/dlls/usp10/opentype.c
> +++ b/dlls/usp10/opentype.c
> @@ -1237,7 +1237,6 @@ static INT GSUB_apply_ChainContextSubst(const OT_LookupList* lookup, const OT_Lo
>          }
>          else if (GET_BE_WORD(ccsf1->SubstFormat) == 2)
>          {
> -            int newIndex = glyph_index;
>              WORD offset, count;
>              const void *backtrack_class_table;
>              const void *input_class_table;
> @@ -1281,12 +1280,13 @@ static INT GSUB_apply_ChainContextSubst(const OT_LookupList* lookup, const OT_Lo
>  
>              for (i = 0; i < count; i++)
>              {
> -                WORD backtrack_count, input_count, lookahead_count;
> +                WORD backtrack_count, input_count, lookahead_count, substitute_count;
>                  int k;
>                  const GSUB_ChainSubClassRule_1 *backtrack;
>                  const GSUB_ChainSubClassRule_2 *input;
>                  const GSUB_ChainSubClassRule_3 *lookahead;
>                  const GSUB_ChainSubClassRule_4 *substitute;
> +                int new_index = GSUB_E_NOGLYPH;
>  
>                  offset = GET_BE_WORD(csc->ChainSubClassRule[i]);
>                  backtrack = (const GSUB_ChainSubClassRule_1 *)((BYTE *)csc + offset);
> @@ -1343,35 +1343,30 @@ static INT GSUB_apply_ChainContextSubst(const OT_LookupList* lookup, const OT_Lo
>                      continue;
>                  TRACE("Matched LookAhead\n");
>  
> -                if (GET_BE_WORD(substitute->SubstCount))
> +                substitute_count = GET_BE_WORD(substitute->SubstCount);
> +                for (k = 0; k < substitute_count; ++k)
>                  {
> -                    for (k = 0; k < GET_BE_WORD(substitute->SubstCount); ++k)
> -                    {
> -                        int lookupIndex = GET_BE_WORD(substitute->SubstLookupRecord[k].LookupListIndex);
> -                        int SequenceIndex = GET_BE_WORD(substitute->SubstLookupRecord[k].SequenceIndex) * write_dir;
> -
> -                        TRACE("SUBST: %i -> %i %i\n",k, SequenceIndex, lookupIndex);
> -                        newIndex = GSUB_apply_lookup(lookup, lookupIndex, glyphs, glyph_index + SequenceIndex, write_dir, glyph_count);
> -                        if (newIndex == GSUB_E_NOGLYPH)
> -                        {
> -                            ERR("Chain failed to generate a glyph\n");
> -                            continue;
> -                        }
> -                    }
> -                    return newIndex;
> +                    WORD lookup_index = GET_BE_WORD(substitute->SubstLookupRecord[k].LookupListIndex);
> +                    WORD sequence_index = GET_BE_WORD(substitute->SubstLookupRecord[k].SequenceIndex) * write_dir;
> +
> +                    TRACE("SUBST: %u -> %u %u.\n", k, sequence_index, lookup_index);
> +                    new_index = GSUB_apply_lookup(lookup, lookup_index, glyphs,
> +                            glyph_index + sequence_index, write_dir, glyph_count);
> +                    if (new_index == GSUB_E_NOGLYPH)
> +                        ERR("Chain failed to generate a glyph.\n");
>                  }
> -                else return GSUB_E_NOGLYPH;
> +                return new_index;
>              }
>          }
>          else if (GET_BE_WORD(ccsf1->SubstFormat) == 3)
>          {
> -            WORD backtrack_count, input_count, lookahead_count;
> +            WORD backtrack_count, input_count, lookahead_count, substitution_count;
>              int k;
>              const GSUB_ChainContextSubstFormat3_1 *backtrack;
>              const GSUB_ChainContextSubstFormat3_2 *input;
>              const GSUB_ChainContextSubstFormat3_3 *lookahead;
>              const GSUB_ChainContextSubstFormat3_4 *substitute;
> -            int newIndex = glyph_index;
> +            int new_index = GSUB_E_NOGLYPH;
>  
>              TRACE("  subtype 3 (Coverage-based Chaining Context Glyph Substitution)\n");
>  
> @@ -1428,24 +1423,19 @@ static INT GSUB_apply_ChainContextSubst(const OT_LookupList* lookup, const OT_Lo
>                  continue;
>              TRACE("Matched LookAhead\n");
>  
> -            if (GET_BE_WORD(substitute->SubstCount))
> +            substitution_count = GET_BE_WORD(substitute->SubstCount);
> +            for (k = 0; k < substitution_count; ++k)
>              {
> -                for (k = 0; k < GET_BE_WORD(substitute->SubstCount); ++k)
> -                {
> -                    int lookupIndex = GET_BE_WORD(substitute->SubstLookupRecord[k].LookupListIndex);
> -                    int SequenceIndex = GET_BE_WORD(substitute->SubstLookupRecord[k].SequenceIndex) * write_dir;
> -
> -                    TRACE("SUBST: %i -> %i %i\n",k, SequenceIndex, lookupIndex);
> -                    newIndex = GSUB_apply_lookup(lookup, lookupIndex, glyphs, glyph_index + SequenceIndex, write_dir, glyph_count);
> -                    if (newIndex == GSUB_E_NOGLYPH)
> -                    {
> -                        ERR("Chain failed to generate a glyph\n");
> -                        continue;
> -                    }
> -                }
> -                return newIndex;
> +                WORD lookup_index = GET_BE_WORD(substitute->SubstLookupRecord[k].LookupListIndex);
> +                WORD sequence_index = GET_BE_WORD(substitute->SubstLookupRecord[k].SequenceIndex) * write_dir;
> +
> +                TRACE("SUBST: %u -> %u %u.\n", k, sequence_index, lookup_index);
> +                new_index = GSUB_apply_lookup(lookup, lookup_index, glyphs,
> +                        glyph_index + sequence_index, write_dir, glyph_count);
> +                if (new_index == GSUB_E_NOGLYPH)
> +                    ERR("Chain failed to generate a glyph.\n");
>              }
> -            else return GSUB_E_NOGLYPH;
> +            return new_index;
>          }
>      }
>      return GSUB_E_NOGLYPH;
>