Merge branch 'nd/diff-parseopt'
authorJunio C Hamano <gitster@pobox.com>
Thu, 30 May 2019 17:50:44 +0000 (10:50 -0700)
committerJunio C Hamano <gitster@pobox.com>
Thu, 30 May 2019 17:50:44 +0000 (10:50 -0700)
A brown-paper-bag bugfix to a change already in 'master'.

* nd/diff-parseopt:
parse-options: check empty value in OPT_INTEGER and OPT_ABBREV
diff-parseopt: restore -U (no argument) behavior
diff-parseopt: correct variable types that are used by parseopt

1  2 
diff.c
diff.h
parse-options-cb.c
parse-options.c
t/t4013-diff-various.sh
diff --combined diff.c
index 4d3cf83a27e5785f5fd50dd2ce6155c94eb50840,0abab4a0b1d51acdc85ab5d0a30f87bb004c2027..80ddc1167157d9da5d6426e9bb548f67705c2c19
--- 1/diff.c
--- 2/diff.c
+++ b/diff.c
@@@ -25,7 -25,6 +25,7 @@@
  #include "packfile.h"
  #include "parse-options.h"
  #include "help.h"
 +#include "fetch-object.h"
  
  #ifdef NO_FAST_WORKING_DIRECTORY
  #define FAST_WORKING_DIRECTORY 0
@@@ -105,6 -104,11 +105,6 @@@ static const char *color_diff_slots[] 
        [DIFF_FILE_NEW_BOLD]          = "newBold",
  };
  
 -static NORETURN void die_want_option(const char *option_name)
 -{
 -      die(_("option '%s' requires a value"), option_name);
 -}
 -
  define_list_config_array_extra(color_diff_slots, {"plain"});
  
  static int parse_diff_color_slot(const char *var)
@@@ -175,10 -179,6 +175,10 @@@ static int parse_submodule_params(struc
                options->submodule_format = DIFF_SUBMODULE_SHORT;
        else if (!strcmp(value, "diff"))
                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 +      /*
 +       * Please update $__git_diff_submodule_formats in
 +       * git-completion.bash when you add new formats.
 +       */
        else
                return -1;
        return 0;
@@@ -205,10 -205,6 +205,10 @@@ long parse_algorithm_value(const char *
                return XDF_PATIENCE_DIFF;
        else if (!strcasecmp(value, "histogram"))
                return XDF_HISTOGRAM_DIFF;
 +      /*
 +       * Please update $__git_diff_algorithms in git-completion.bash
 +       * when you add new algorithms.
 +       */
        return -1;
  }
  
@@@ -309,9 -305,7 +309,9 @@@ static unsigned parse_color_moved_ws(co
                strbuf_addstr(&sb, i->string);
                strbuf_trim(&sb);
  
 -              if (!strcmp(sb.buf, "ignore-space-change"))
 +              if (!strcmp(sb.buf, "no"))
 +                      ret = 0;
 +              else if (!strcmp(sb.buf, "ignore-space-change"))
                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
  
        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
            (ret & XDF_WHITESPACE_FLAGS)) {
 -              error(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 +              error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
                ret |= COLOR_MOVED_WS_ERROR;
        }
  
@@@ -500,7 -494,7 +500,7 @@@ static const char *external_diff(void
  
        if (done_preparing)
                return external_diff_cmd;
 -      external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 +      external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
        if (!external_diff_cmd)
                external_diff_cmd = external_diff_cmd_cfg;
        done_preparing = 1;
@@@ -761,8 -755,6 +761,8 @@@ struct emitted_diff_symbol 
        const char *line;
        int len;
        int flags;
 +      int indent_off;   /* Offset to first non-whitespace character */
 +      int indent_width; /* The visual width of the indentation */
        enum diff_symbol s;
  };
  #define EMITTED_DIFF_SYMBOL_INIT {NULL}
@@@ -793,85 -785,44 +793,85 @@@ struct moved_entry 
        struct moved_entry *next_line;
  };
  
 -/**
 - * The struct ws_delta holds white space differences between moved lines, i.e.
 - * between '+' and '-' lines that have been detected to be a move.
 - * The string contains the difference in leading white spaces, before the
 - * rest of the line is compared using the white space config for move
 - * coloring. The current_longer indicates if the first string in the
 - * comparision is longer than the second.
 - */
 -struct ws_delta {
 -      char *string;
 -      unsigned int current_longer : 1;
 -};
 -#define WS_DELTA_INIT { NULL, 0 }
 -
  struct moved_block {
        struct moved_entry *match;
 -      struct ws_delta wsd;
 +      int wsd; /* The whitespace delta of this block */
  };
  
  static void moved_block_clear(struct moved_block *b)
  {
 -      FREE_AND_NULL(b->wsd.string);
 -      b->match = NULL;
 +      memset(b, 0, sizeof(*b));
  }
  
 -static int compute_ws_delta(const struct emitted_diff_symbol *a,
 -                           const struct emitted_diff_symbol *b,
 -                           struct ws_delta *out)
 +#define INDENT_BLANKLINE INT_MIN
 +
 +static void fill_es_indent_data(struct emitted_diff_symbol *es)
  {
 -      const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 -      const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 -      int d = longer->len - shorter->len;
 +      unsigned int off = 0, i;
 +      int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
 +      const char *s = es->line;
 +      const int len = es->len;
 +
 +      /* skip any \v \f \r at start of indentation */
 +      while (s[off] == '\f' || s[off] == '\v' ||
 +             (s[off] == '\r' && off < len - 1))
 +              off++;
 +
 +      /* calculate the visual width of indentation */
 +      while(1) {
 +              if (s[off] == ' ') {
 +                      width++;
 +                      off++;
 +              } else if (s[off] == '\t') {
 +                      width += tab_width - (width % tab_width);
 +                      while (s[++off] == '\t')
 +                              width += tab_width;
 +              } else {
 +                      break;
 +              }
 +      }
 +
 +      /* check if this line is blank */
 +      for (i = off; i < len; i++)
 +              if (!isspace(s[i]))
 +                  break;
 +
 +      if (i == len) {
 +              es->indent_width = INDENT_BLANKLINE;
 +              es->indent_off = len;
 +      } else {
 +              es->indent_off = off;
 +              es->indent_width = width;
 +      }
 +}
  
 -      if (strncmp(longer->line + d, shorter->line, shorter->len))
 +static int compute_ws_delta(const struct emitted_diff_symbol *a,
 +                          const struct emitted_diff_symbol *b,
 +                          int *out)
 +{
 +      int a_len = a->len,
 +          b_len = b->len,
 +          a_off = a->indent_off,
 +          a_width = a->indent_width,
 +          b_off = b->indent_off,
 +          b_width = b->indent_width;
 +      int delta;
 +
 +      if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 +              *out = INDENT_BLANKLINE;
 +              return 1;
 +      }
 +
 +      if (a->s == DIFF_SYMBOL_PLUS)
 +              delta = a_width - b_width;
 +      else
 +              delta = b_width - a_width;
 +
 +      if (a_len - a_off != b_len - b_off ||
 +          memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
                return 0;
  
 -      out->string = xmemdupz(longer->line, d);
 -      out->current_longer = (a == longer);
 +      *out = delta;
  
        return 1;
  }
@@@ -883,53 -834,51 +883,53 @@@ static int cmp_in_block_with_wsd(const 
                                 int n)
  {
        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 -      int al = cur->es->len, cl = l->len;
 +      int al = cur->es->len, bl = match->es->len, cl = l->len;
        const char *a = cur->es->line,
                   *b = match->es->line,
                   *c = l->line;
 -
 -      int wslen;
 +      int a_off = cur->es->indent_off,
 +          a_width = cur->es->indent_width,
 +          c_off = l->indent_off,
 +          c_width = l->indent_width;
 +      int delta;
  
        /*
 -       * We need to check if 'cur' is equal to 'match'.
 -       * As those are from the same (+/-) side, we do not need to adjust for
 -       * indent changes. However these were found using fuzzy matching
 -       * so we do have to check if they are equal.
 +       * We need to check if 'cur' is equal to 'match'.  As those
 +       * are from the same (+/-) side, we do not need to adjust for
 +       * indent changes. However these were found using fuzzy
 +       * matching so we do have to check if they are equal. Here we
 +       * just check the lengths. We delay calling memcmp() to check
 +       * the contents until later as if the length comparison for a
 +       * and c fails we can avoid the call all together.
         */
 -      if (strcmp(a, b))
 +      if (al != bl)
                return 1;
  
 -      if (!pmb->wsd.string)
 -              /*
 -               * The white space delta is not active? This can happen
 -               * when we exit early in this function.
 -               */
 -              return 1;
 +      /* If 'l' and 'cur' are both blank then they match. */
 +      if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
 +              return 0;
  
        /*
 -       * The indent changes of the block are known and stored in
 -       * pmb->wsd; however we need to check if the indent changes of the
 -       * current line are still the same as before.
 -       *
 -       * To do so we need to compare 'l' to 'cur', adjusting the
 -       * one of them for the white spaces, depending which was longer.
 +       * The indent changes of the block are known and stored in pmb->wsd;
 +       * however we need to check if the indent changes of the current line
 +       * match those of the current block and that the text of 'l' and 'cur'
 +       * after the indentation match.
         */
 +      if (cur->es->s == DIFF_SYMBOL_PLUS)
 +              delta = a_width - c_width;
 +      else
 +              delta = c_width - a_width;
  
 -      wslen = strlen(pmb->wsd.string);
 -      if (pmb->wsd.current_longer) {
 -              c += wslen;
 -              cl -= wslen;
 -      } else {
 -              a += wslen;
 -              al -= wslen;
 -      }
 -
 -      if (al != cl || memcmp(a, c, al))
 -              return 1;
 +      /*
 +       * If the previous lines of this block were all blank then set its
 +       * whitespace delta.
 +       */
 +      if (pmb->wsd == INDENT_BLANKLINE)
 +              pmb->wsd = delta;
  
 -      return 0;
 +      return !(delta == pmb->wsd && al - a_off == cl - c_off &&
 +               !memcmp(a, b, al) && !
 +               memcmp(a + a_off, c + c_off, al - a_off));
  }
  
  static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@@ -995,9 -944,6 +995,9 @@@ static void add_lines_to_move_detection
                        continue;
                }
  
 +              if (o->color_moved_ws_handling &
 +                  COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 +                      fill_es_indent_data(&o->emitted_symbols->buf[n]);
                key = prepare_entry(o, n);
                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
                        prev_line->next_line = key;
@@@ -1076,7 -1022,8 +1076,7 @@@ static int shrink_potential_moved_block
  
                if (lp < pmb_nr && rp > -1 && lp < rp) {
                        pmb[lp] = pmb[rp];
 -                      pmb[rp].match = NULL;
 -                      pmb[rp].wsd.string = NULL;
 +                      memset(&pmb[rp], 0, sizeof(pmb[rp]));
                        rp--;
                        lp++;
                }
   * The last block consists of the (n - block_length)'th line up to but not
   * including the nth line.
   *
 + * Returns 0 if the last block is empty or is unset by this function, non zero
 + * otherwise.
 + *
   * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
   * Think of a way to unify them.
   */
 -static void adjust_last_block(struct diff_options *o, int n, int block_length)
 +static int adjust_last_block(struct diff_options *o, int n, int block_length)
  {
        int i, alnum_count = 0;
        if (o->color_moved == COLOR_MOVED_PLAIN)
 -              return;
 +              return block_length;
        for (i = 1; i < block_length + 1; i++) {
                const char *c = o->emitted_symbols->buf[n - i].line;
                for (; *c; c++) {
                                continue;
                        alnum_count++;
                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
 -                              return;
 +                              return 1;
                }
        }
        for (i = 1; i < block_length + 1; i++)
                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
 +      return 0;
  }
  
  /* Find blocks of moved code, delegate actual coloring decision to helper */
@@@ -1129,7 -1072,7 +1129,7 @@@ static void mark_color_as_moved(struct 
  {
        struct moved_block *pmb = NULL; /* potentially moved blocks */
        int pmb_nr = 0, pmb_alloc = 0;
 -      int n, flipped_block = 1, block_length = 0;
 +      int n, flipped_block = 0, block_length = 0;
  
  
        for (n = 0; n < o->emitted_symbols->nr; n++) {
                struct moved_entry *key;
                struct moved_entry *match = NULL;
                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 +              enum diff_symbol last_symbol = 0;
  
                switch (l->s) {
                case DIFF_SYMBOL_PLUS:
                        free(key);
                        break;
                default:
 -                      flipped_block = 1;
 +                      flipped_block = 0;
                }
  
                if (!match) {
                                moved_block_clear(&pmb[i]);
                        pmb_nr = 0;
                        block_length = 0;
 +                      flipped_block = 0;
 +                      last_symbol = l->s;
                        continue;
                }
  
 -              l->flags |= DIFF_SYMBOL_MOVED_LINE;
 -
 -              if (o->color_moved == COLOR_MOVED_PLAIN)
 +              if (o->color_moved == COLOR_MOVED_PLAIN) {
 +                      last_symbol = l->s;
 +                      l->flags |= DIFF_SYMBOL_MOVED_LINE;
                        continue;
 +              }
  
                if (o->color_moved_ws_handling &
                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
                                                             &pmb[pmb_nr].wsd))
                                                pmb[pmb_nr++].match = match;
                                } else {
 -                                      pmb[pmb_nr].wsd.string = NULL;
 +                                      pmb[pmb_nr].wsd = 0;
                                        pmb[pmb_nr++].match = match;
                                }
                        }
  
 -                      flipped_block = (flipped_block + 1) % 2;
 +                      if (adjust_last_block(o, n, block_length) &&
 +                          pmb_nr && last_symbol != l->s)
 +                              flipped_block = (flipped_block + 1) % 2;
 +                      else
 +                              flipped_block = 0;
  
 -                      adjust_last_block(o, n, block_length);
                        block_length = 0;
                }
  
 -              block_length++;
 -
 -              if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
 -                      l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 +              if (pmb_nr) {
 +                      block_length++;
 +                      l->flags |= DIFF_SYMBOL_MOVED_LINE;
 +                      if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
 +                              l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 +              }
 +              last_symbol = l->s;
        }
        adjust_last_block(o, n, block_length);
  
@@@ -1560,7 -1493,7 +1560,7 @@@ static void emit_diff_symbol_from_struc
  static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
                             const char *line, int len, unsigned flags)
  {
 -      struct emitted_diff_symbol e = {line, len, flags, s};
 +      struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
  
        if (o->emitted_symbols)
                append_emitted_diff_symbol(o, &e);
@@@ -1618,7 -1551,8 +1618,7 @@@ static int new_blank_line_at_eof(struc
        return ws_blank_line(line, len, ecbdata->ws_rule);
  }
  
 -static void emit_add_line(const char *reset,
 -                        struct emit_callback *ecbdata,
 +static void emit_add_line(struct emit_callback *ecbdata,
                          const char *line, int len)
  {
        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
  }
  
 -static void emit_del_line(const char *reset,
 -                        struct emit_callback *ecbdata,
 +static void emit_del_line(struct emit_callback *ecbdata,
                          const char *line, int len)
  {
        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
  }
  
 -static void emit_context_line(const char *reset,
 -                            struct emit_callback *ecbdata,
 +static void emit_context_line(struct emit_callback *ecbdata,
                              const char *line, int len)
  {
        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
@@@ -1744,6 -1680,7 +1744,6 @@@ static void emit_rewrite_lines(struct e
                               int prefix, const char *data, int size)
  {
        const char *endp = NULL;
 -      const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
  
        while (0 < size) {
                int len;
                len = endp ? (endp - data + 1) : size;
                if (prefix != '+') {
                        ecb->lno_in_preimage++;
 -                      emit_del_line(reset, ecb, data, len);
 +                      emit_del_line(ecb, data, len);
                } else {
                        ecb->lno_in_postimage++;
 -                      emit_add_line(reset, ecb, data, len);
 +                      emit_add_line(ecb, data, len);
                }
                size -= len;
                data += len;
@@@ -2292,7 -2229,7 +2292,7 @@@ const char *diff_line_prefix(struct dif
        return msgbuf->buf;
  }
  
 -static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 +static unsigned long sane_truncate_line(char *line, unsigned long len)
  {
        const char *cp;
        unsigned long allot;
@@@ -2326,6 -2263,7 +2326,6 @@@ static void find_lno(const char *line, 
  static void fn_out_consume(void *priv, char *line, unsigned long len)
  {
        struct emit_callback *ecbdata = priv;
 -      const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
        struct diff_options *o = ecbdata->opt;
  
        o->found_changes = 1;
        if (line[0] == '@') {
                if (ecbdata->diff_words)
                        diff_words_flush(ecbdata);
 -              len = sane_truncate_line(ecbdata, line, len);
 +              len = sane_truncate_line(line, len);
                find_lno(line, ecbdata);
                emit_hunk_header(ecbdata, line, len);
                return;
        switch (line[0]) {
        case '+':
                ecbdata->lno_in_postimage++;
 -              emit_add_line(reset, ecbdata, line + 1, len - 1);
 +              emit_add_line(ecbdata, line + 1, len - 1);
                break;
        case '-':
                ecbdata->lno_in_preimage++;
 -              emit_del_line(reset, ecbdata, line + 1, len - 1);
 +              emit_del_line(ecbdata, line + 1, len - 1);
                break;
        case ' ':
                ecbdata->lno_in_postimage++;
                ecbdata->lno_in_preimage++;
 -              emit_context_line(reset, ecbdata, line + 1, len - 1);
 +              emit_context_line(ecbdata, line + 1, len - 1);
                break;
        default:
                /* incomplete line at the end */
@@@ -3544,7 -3482,7 +3544,7 @@@ static void builtin_diff(const char *na
                o->found_changes = 1;
        } else {
                /* Crazy xdl interfaces.. */
 -              const char *diffopts = getenv("GIT_DIFF_OPTS");
 +              const char *diffopts;
                const char *v;
                xpparam_t xpp;
                xdemitconf_t xecfg;
                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
                if (pe)
                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
 +
 +              diffopts = getenv("GIT_DIFF_OPTS");
                if (!diffopts)
                        ;
                else if (skip_prefix(diffopts, "--unified=", &v))
                        xecfg.ctxlen = strtoul(v, NULL, 10);
                else if (skip_prefix(diffopts, "-u", &v))
                        xecfg.ctxlen = strtoul(v, NULL, 10);
 +
                if (o->word_diff)
                        init_diff_words_data(&ecbdata, o, one, two);
                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
@@@ -4183,6 -4118,7 +4183,6 @@@ static void run_external_diff(const cha
                              struct diff_filespec *one,
                              struct diff_filespec *two,
                              const char *xfrm_msg,
 -                            int complete_rewrite,
                              struct diff_options *o)
  {
        struct argv_array argv = ARGV_ARRAY_INIT;
@@@ -4340,7 -4276,8 +4340,7 @@@ static void run_diff_cmd(const char *pg
        }
  
        if (pgm) {
 -              run_external_diff(pgm, name, other, one, two, xfrm_msg,
 -                                complete_rewrite, o);
 +              run_external_diff(pgm, name, other, one, two, xfrm_msg, o);
                return;
        }
        if (one && two)
@@@ -4641,6 -4578,68 +4641,6 @@@ void diff_setup_done(struct diff_option
        FREE_AND_NULL(options->parseopts);
  }
  
 -static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
 -{
 -      char c, *eq;
 -      int len;
 -
 -      if (*arg != '-')
 -              return 0;
 -      c = *++arg;
 -      if (!c)
 -              return 0;
 -      if (c == arg_short) {
 -              c = *++arg;
 -              if (!c)
 -                      return 1;
 -              if (val && isdigit(c)) {
 -                      char *end;
 -                      int n = strtoul(arg, &end, 10);
 -                      if (*end)
 -                              return 0;
 -                      *val = n;
 -                      return 1;
 -              }
 -              return 0;
 -      }
 -      if (c != '-')
 -              return 0;
 -      arg++;
 -      eq = strchrnul(arg, '=');
 -      len = eq - arg;
 -      if (!len || strncmp(arg, arg_long, len))
 -              return 0;
 -      if (*eq) {
 -              int n;
 -              char *end;
 -              if (!isdigit(*++eq))
 -                      return 0;
 -              n = strtoul(eq, &end, 10);
 -              if (*end)
 -                      return 0;
 -              *val = n;
 -      }
 -      return 1;
 -}
 -
 -static int diff_scoreopt_parse(const char *opt);
 -
 -static inline int short_opt(char opt, const char **argv,
 -                          const char **optarg)
 -{
 -      const char *arg = argv[0];
 -      if (arg[0] != '-' || arg[1] != opt)
 -              return 0;
 -      if (arg[2] != '\0') {
 -              *optarg = arg + 2;
 -              return 1;
 -      }
 -      if (!argv[1])
 -              die("Option '%c' requires a value", opt);
 -      *optarg = argv[1];
 -      return 2;
 -}
 -
  int parse_long_opt(const char *opt, const char **argv,
                   const char **optarg)
  {
        return 2;
  }
  
 -static int stat_opt(struct diff_options *options, const char **av)
 +static int diff_opt_stat(const struct option *opt, const char *value, int unset)
  {
 -      const char *arg = av[0];
 -      char *end;
 +      struct diff_options *options = opt->value;
        int width = options->stat_width;
        int name_width = options->stat_name_width;
        int graph_width = options->stat_graph_width;
        int count = options->stat_count;
 -      int argcount = 1;
 +      char *end;
  
 -      if (!skip_prefix(arg, "--stat", &arg))
 -              BUG("stat option does not begin with --stat: %s", arg);
 -      end = (char *)arg;
 +      BUG_ON_OPT_NEG(unset);
  
 -      switch (*arg) {
 -      case '-':
 -              if (skip_prefix(arg, "-width", &arg)) {
 -                      if (*arg == '=')
 -                              width = strtoul(arg + 1, &end, 10);
 -                      else if (!*arg && !av[1])
 -                              die_want_option("--stat-width");
 -                      else if (!*arg) {
 -                              width = strtoul(av[1], &end, 10);
 -                              argcount = 2;
 -                      }
 -              } else if (skip_prefix(arg, "-name-width", &arg)) {
 -                      if (*arg == '=')
 -                              name_width = strtoul(arg + 1, &end, 10);
 -                      else if (!*arg && !av[1])
 -                              die_want_option("--stat-name-width");
 -                      else if (!*arg) {
 -                              name_width = strtoul(av[1], &end, 10);
 -                              argcount = 2;
 -                      }
 -              } else if (skip_prefix(arg, "-graph-width", &arg)) {
 -                      if (*arg == '=')
 -                              graph_width = strtoul(arg + 1, &end, 10);
 -                      else if (!*arg && !av[1])
 -                              die_want_option("--stat-graph-width");
 -                      else if (!*arg) {
 -                              graph_width = strtoul(av[1], &end, 10);
 -                              argcount = 2;
 -                      }
 -              } else if (skip_prefix(arg, "-count", &arg)) {
 -                      if (*arg == '=')
 -                              count = strtoul(arg + 1, &end, 10);
 -                      else if (!*arg && !av[1])
 -                              die_want_option("--stat-count");
 -                      else if (!*arg) {
 -                              count = strtoul(av[1], &end, 10);
 -                              argcount = 2;
 -                      }
 +      if (!strcmp(opt->long_name, "stat")) {
 +              if (value) {
 +                      width = strtoul(value, &end, 10);
 +                      if (*end == ',')
 +                              name_width = strtoul(end+1, &end, 10);
 +                      if (*end == ',')
 +                              count = strtoul(end+1, &end, 10);
 +                      if (*end)
 +                              return error(_("invalid --stat value: %s"), value);
                }
 -              break;
 -      case '=':
 -              width = strtoul(arg+1, &end, 10);
 -              if (*end == ',')
 -                      name_width = strtoul(end+1, &end, 10);
 -              if (*end == ',')
 -                      count = strtoul(end+1, &end, 10);
 -      }
 +      } else if (!strcmp(opt->long_name, "stat-width")) {
 +              width = strtoul(value, &end, 10);
 +              if (*end)
 +                      return error(_("%s expects a numerical value"),
 +                                   opt->long_name);
 +      } else if (!strcmp(opt->long_name, "stat-name-width")) {
 +              name_width = strtoul(value, &end, 10);
 +              if (*end)
 +                      return error(_("%s expects a numerical value"),
 +                                   opt->long_name);
 +      } else if (!strcmp(opt->long_name, "stat-graph-width")) {
 +              graph_width = strtoul(value, &end, 10);
 +              if (*end)
 +                      return error(_("%s expects a numerical value"),
 +                                   opt->long_name);
 +      } else if (!strcmp(opt->long_name, "stat-count")) {
 +              count = strtoul(value, &end, 10);
 +              if (*end)
 +                      return error(_("%s expects a numerical value"),
 +                                   opt->long_name);
 +      } else
 +              BUG("%s should not get here", opt->long_name);
  
 -      /* Important! This checks all the error cases! */
 -      if (*end)
 -              return 0;
        options->output_format |= DIFF_FORMAT_DIFFSTAT;
        options->stat_name_width = name_width;
        options->stat_graph_width = graph_width;
        options->stat_width = width;
        options->stat_count = count;
 -      return argcount;
 +      return 0;
  }
  
  static int parse_dirstat_opt(struct diff_options *options, const char *params)
        return 1;
  }
  
 -static int parse_submodule_opt(struct diff_options *options, const char *value)
 -{
 -      if (parse_submodule_params(options, value))
 -              die(_("Failed to parse --submodule option parameter: '%s'"),
 -                      value);
 -      return 1;
 -}
 -
  static const char diff_status_letters[] = {
        DIFF_STATUS_ADDED,
        DIFF_STATUS_COPIED,
@@@ -4760,19 -4788,10 +4760,19 @@@ static unsigned filter_bit_tst(char sta
        return opt->filter & filter_bit[(int) status];
  }
  
 -static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
 +unsigned diff_filter_bit(char status)
 +{
 +      prepare_filter_bits();
 +      return filter_bit[(int) status];
 +}
 +
 +static int diff_opt_diff_filter(const struct option *option,
 +                              const char *optarg, int unset)
  {
 +      struct diff_options *opt = option->value;
        int i, optch;
  
 +      BUG_ON_OPT_NEG(unset);
        prepare_filter_bits();
  
        /*
  
                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
                if (!bit)
 -                      return optarg[i];
 +                      return error(_("unknown change class '%c' in --diff-filter=%s"),
 +                                   optarg[i], optarg);
                if (negate)
                        opt->filter &= ~bit;
                else
@@@ -4819,29 -4837,25 +4819,29 @@@ static void enable_patch_output(int *fm
        *fmt |= DIFF_FORMAT_PATCH;
  }
  
 -static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
 +static int diff_opt_ws_error_highlight(const struct option *option,
 +                                     const char *arg, int unset)
  {
 +      struct diff_options *opt = option->value;
        int val = parse_ws_error_highlight(arg);
  
 -      if (val < 0) {
 -              error("unknown value after ws-error-highlight=%.*s",
 -                    -1 - val, arg);
 -              return 0;
 -      }
 +      BUG_ON_OPT_NEG(unset);
 +      if (val < 0)
 +              return error(_("unknown value after ws-error-highlight=%.*s"),
 +                           -1 - val, arg);
        opt->ws_error_highlight = val;
 -      return 1;
 +      return 0;
  }
  
 -static int parse_objfind_opt(struct diff_options *opt, const char *arg)
 +static int diff_opt_find_object(const struct option *option,
 +                              const char *arg, int unset)
  {
 +      struct diff_options *opt = option->value;
        struct object_id oid;
  
 +      BUG_ON_OPT_NEG(unset);
        if (get_oid(arg, &oid))
 -              return error("unable to resolve '%s'", arg);
 +              return error(_("unable to resolve '%s'"), arg);
  
        if (!opt->objfind)
                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
        opt->flags.recursive = 1;
        opt->flags.tree_in_recursive = 1;
        oidset_insert(opt->objfind, &oid);
 -      return 1;
 +      return 0;
 +}
 +
 +static int diff_opt_anchored(const struct option *opt,
 +                           const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
 +      ALLOC_GROW(options->anchors, options->anchors_nr + 1,
 +                 options->anchors_alloc);
 +      options->anchors[options->anchors_nr++] = xstrdup(arg);
 +      return 0;
 +}
 +
 +static int diff_opt_binary(const struct option *opt,
 +                         const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      BUG_ON_OPT_ARG(arg);
 +      enable_patch_output(&options->output_format);
 +      options->flags.binary = 1;
 +      return 0;
 +}
 +
 +static int diff_opt_break_rewrites(const struct option *opt,
 +                                 const char *arg, int unset)
 +{
 +      int *break_opt = opt->value;
 +      int opt1, opt2;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (!arg)
 +              arg = "";
 +      opt1 = parse_rename_score(&arg);
 +      if (*arg == 0)
 +              opt2 = 0;
 +      else if (*arg != '/')
 +              return error(_("%s expects <n>/<m> form"), opt->long_name);
 +      else {
 +              arg++;
 +              opt2 = parse_rename_score(&arg);
 +      }
 +      if (*arg != 0)
 +              return error(_("%s expects <n>/<m> form"), opt->long_name);
 +      *break_opt = opt1 | (opt2 << 16);
 +      return 0;
 +}
 +
 +static int diff_opt_char(const struct option *opt,
 +                       const char *arg, int unset)
 +{
 +      char *value = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (arg[1])
 +              return error(_("%s expects a character, got '%s'"),
 +                           opt->long_name, arg);
 +      *value = arg[0];
 +      return 0;
 +}
 +
 +static int diff_opt_color_moved(const struct option *opt,
 +                              const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      if (unset) {
 +              options->color_moved = COLOR_MOVED_NO;
 +      } else if (!arg) {
 +              if (diff_color_moved_default)
 +                      options->color_moved = diff_color_moved_default;
 +              if (options->color_moved == COLOR_MOVED_NO)
 +                      options->color_moved = COLOR_MOVED_DEFAULT;
 +      } else {
 +              int cm = parse_color_moved(arg);
 +              if (cm < 0)
 +                      return error(_("bad --color-moved argument: %s"), arg);
 +              options->color_moved = cm;
 +      }
 +      return 0;
 +}
 +
 +static int diff_opt_color_moved_ws(const struct option *opt,
 +                                 const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +      unsigned cm;
 +
 +      if (unset) {
 +              options->color_moved_ws_handling = 0;
 +              return 0;
 +      }
 +
 +      cm = parse_color_moved_ws(arg);
 +      if (cm & COLOR_MOVED_WS_ERROR)
 +              return error(_("invalid mode '%s' in --color-moved-ws"), arg);
 +      options->color_moved_ws_handling = cm;
 +      return 0;
 +}
 +
 +static int diff_opt_color_words(const struct option *opt,
 +                              const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      options->use_color = 1;
 +      options->word_diff = DIFF_WORDS_COLOR;
 +      options->word_regex = arg;
 +      return 0;
 +}
 +
 +static int diff_opt_compact_summary(const struct option *opt,
 +                                  const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_ARG(arg);
 +      if (unset) {
 +              options->flags.stat_with_summary = 0;
 +      } else {
 +              options->flags.stat_with_summary = 1;
 +              options->output_format |= DIFF_FORMAT_DIFFSTAT;
 +      }
 +      return 0;
 +}
 +
 +static int diff_opt_diff_algorithm(const struct option *opt,
 +                                 const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +      long value = parse_algorithm_value(arg);
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (value < 0)
 +              return error(_("option diff-algorithm accepts \"myers\", "
 +                             "\"minimal\", \"patience\" and \"histogram\""));
 +
 +      /* clear out previous settings */
 +      DIFF_XDL_CLR(options, NEED_MINIMAL);
 +      options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
 +      options->xdl_opts |= value;
 +      return 0;
 +}
 +
 +static int diff_opt_dirstat(const struct option *opt,
 +                          const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (!strcmp(opt->long_name, "cumulative")) {
 +              if (arg)
 +                      BUG("how come --cumulative take a value?");
 +              arg = "cumulative";
 +      } else if (!strcmp(opt->long_name, "dirstat-by-file"))
 +              parse_dirstat_opt(options, "files");
 +      parse_dirstat_opt(options, arg ? arg : "");
 +      return 0;
 +}
 +
 +static int diff_opt_find_copies(const struct option *opt,
 +                              const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (!arg)
 +              arg = "";
 +      options->rename_score = parse_rename_score(&arg);
 +      if (*arg != 0)
 +              return error(_("invalid argument to %s"), opt->long_name);
 +
 +      if (options->detect_rename == DIFF_DETECT_COPY)
 +              options->flags.find_copies_harder = 1;
 +      else
 +              options->detect_rename = DIFF_DETECT_COPY;
 +
 +      return 0;
 +}
 +
 +static int diff_opt_find_renames(const struct option *opt,
 +                               const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (!arg)
 +              arg = "";
 +      options->rename_score = parse_rename_score(&arg);
 +      if (*arg != 0)
 +              return error(_("invalid argument to %s"), opt->long_name);
 +
 +      options->detect_rename = DIFF_DETECT_RENAME;
 +      return 0;
 +}
 +
 +static int diff_opt_follow(const struct option *opt,
 +                         const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_ARG(arg);
 +      if (unset) {
 +              options->flags.follow_renames = 0;
 +              options->flags.default_follow_renames = 0;
 +      } else {
 +              options->flags.follow_renames = 1;
 +      }
 +      return 0;
 +}
 +
 +static int diff_opt_ignore_submodules(const struct option *opt,
 +                                    const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (!arg)
 +              arg = "all";
 +      options->flags.override_submodule_config = 1;
 +      handle_ignore_submodules_arg(options, arg);
 +      return 0;
 +}
 +
 +static int diff_opt_line_prefix(const struct option *opt,
 +                              const char *optarg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      options->line_prefix = optarg;
 +      options->line_prefix_length = strlen(options->line_prefix);
 +      graph_setup_line_prefix(options);
 +      return 0;
 +}
 +
 +static int diff_opt_no_prefix(const struct option *opt,
 +                            const char *optarg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      BUG_ON_OPT_ARG(optarg);
 +      options->a_prefix = "";
 +      options->b_prefix = "";
 +      return 0;
 +}
 +
 +static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
 +                                           const struct option *opt,
 +                                           const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +      char *path;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      path = prefix_filename(ctx->prefix, arg);
 +      options->file = xfopen(path, "w");
 +      options->close_file = 1;
 +      if (options->use_color != GIT_COLOR_ALWAYS)
 +              options->use_color = GIT_COLOR_NEVER;
 +      free(path);
 +      return 0;
 +}
 +
 +static int diff_opt_patience(const struct option *opt,
 +                           const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +      int i;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      BUG_ON_OPT_ARG(arg);
 +      options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
 +      /*
 +       * Both --patience and --anchored use PATIENCE_DIFF
 +       * internally, so remove any anchors previously
 +       * specified.
 +       */
 +      for (i = 0; i < options->anchors_nr; i++)
 +              free(options->anchors[i]);
 +      options->anchors_nr = 0;
 +      return 0;
 +}
 +
 +static int diff_opt_pickaxe_regex(const struct option *opt,
 +                                const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      options->pickaxe = arg;
 +      options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
 +      return 0;
 +}
 +
 +static int diff_opt_pickaxe_string(const struct option *opt,
 +                                 const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      options->pickaxe = arg;
 +      options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
 +      return 0;
 +}
 +
 +static int diff_opt_relative(const struct option *opt,
 +                           const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      options->flags.relative_name = 1;
 +      if (arg)
 +              options->prefix = arg;
 +      return 0;
 +}
 +
 +static int diff_opt_submodule(const struct option *opt,
 +                            const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (!arg)
 +              arg = "log";
 +      if (parse_submodule_params(options, arg))
 +              return error(_("failed to parse --submodule option parameter: '%s'"),
 +                           arg);
 +      return 0;
 +}
 +
 +static int diff_opt_textconv(const struct option *opt,
 +                           const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_ARG(arg);
 +      if (unset) {
 +              options->flags.allow_textconv = 0;
 +      } else {
 +              options->flags.allow_textconv = 1;
 +              options->flags.textconv_set_via_cmdline = 1;
 +      }
 +      return 0;
  }
  
  static int diff_opt_unified(const struct option *opt,
  
        BUG_ON_OPT_NEG(unset);
  
-       options->context = strtol(arg, &s, 10);
-       if (*s)
-               return error(_("%s expects a numerical value"), "--unified");
+       if (arg) {
+               options->context = strtol(arg, &s, 10);
+               if (*s)
+                       return error(_("%s expects a numerical value"), "--unified");
+       }
        enable_patch_output(&options->output_format);
  
        return 0;
  }
  
 +static int diff_opt_word_diff(const struct option *opt,
 +                            const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (arg) {
 +              if (!strcmp(arg, "plain"))
 +                      options->word_diff = DIFF_WORDS_PLAIN;
 +              else if (!strcmp(arg, "color")) {
 +                      options->use_color = 1;
 +                      options->word_diff = DIFF_WORDS_COLOR;
 +              }
 +              else if (!strcmp(arg, "porcelain"))
 +                      options->word_diff = DIFF_WORDS_PORCELAIN;
 +              else if (!strcmp(arg, "none"))
 +                      options->word_diff = DIFF_WORDS_NONE;
 +              else
 +                      return error(_("bad --word-diff argument: %s"), arg);
 +      } else {
 +              if (options->word_diff == DIFF_WORDS_NONE)
 +                      options->word_diff = DIFF_WORDS_PLAIN;
 +      }
 +      return 0;
 +}
 +
 +static int diff_opt_word_diff_regex(const struct option *opt,
 +                                  const char *arg, int unset)
 +{
 +      struct diff_options *options = opt->value;
 +
 +      BUG_ON_OPT_NEG(unset);
 +      if (options->word_diff == DIFF_WORDS_NONE)
 +              options->word_diff = DIFF_WORDS_PLAIN;
 +      options->word_regex = arg;
 +      return 0;
 +}
 +
  static void prep_parse_options(struct diff_options *options)
  {
        struct option parseopts[] = {
                OPT_BITOP('p', "patch", &options->output_format,
                          N_("generate patch"),
                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
 +              OPT_BIT_F('s', "no-patch", &options->output_format,
 +                        N_("suppress diff output"),
 +                        DIFF_FORMAT_NO_OUTPUT, PARSE_OPT_NONEG),
                OPT_BITOP('u', NULL, &options->output_format,
                          N_("generate patch"),
                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
                OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
                               N_("generate diffs with <n> lines context"),
-                              PARSE_OPT_NONEG, diff_opt_unified),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_unified),
                OPT_BOOL('W', "function-context", &options->flags.funccontext,
                         N_("generate diffs with <n> lines context")),
                OPT_BIT_F(0, "raw", &options->output_format,
                          N_("generate the diff in raw format"),
                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
 +              OPT_BITOP(0, "patch-with-raw", &options->output_format,
 +                        N_("synonym for '-p --raw'"),
 +                        DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW,
 +                        DIFF_FORMAT_NO_OUTPUT),
 +              OPT_BITOP(0, "patch-with-stat", &options->output_format,
 +                        N_("synonym for '-p --stat'"),
 +                        DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT,
 +                        DIFF_FORMAT_NO_OUTPUT),
 +              OPT_BIT_F(0, "numstat", &options->output_format,
 +                        N_("machine friendly --stat"),
 +                        DIFF_FORMAT_NUMSTAT, PARSE_OPT_NONEG),
 +              OPT_BIT_F(0, "shortstat", &options->output_format,
 +                        N_("output only the last line of --stat"),
 +                        DIFF_FORMAT_SHORTSTAT, PARSE_OPT_NONEG),
 +              OPT_CALLBACK_F('X', "dirstat", options, N_("<param1,param2>..."),
 +                             N_("output the distribution of relative amount of changes for each sub-directory"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 +                             diff_opt_dirstat),
 +              OPT_CALLBACK_F(0, "cumulative", options, NULL,
 +                             N_("synonym for --dirstat=cumulative"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_NOARG,
 +                             diff_opt_dirstat),
 +              OPT_CALLBACK_F(0, "dirstat-by-file", options, N_("<param1,param2>..."),
 +                             N_("synonym for --dirstat=files,param1,param2..."),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 +                             diff_opt_dirstat),
 +              OPT_BIT_F(0, "check", &options->output_format,
 +                        N_("warn if changes introduce conflict markers or whitespace errors"),
 +                        DIFF_FORMAT_CHECKDIFF, PARSE_OPT_NONEG),
 +              OPT_BIT_F(0, "summary", &options->output_format,
 +                        N_("condensed summary such as creations, renames and mode changes"),
 +                        DIFF_FORMAT_SUMMARY, PARSE_OPT_NONEG),
 +              OPT_BIT_F(0, "name-only", &options->output_format,
 +                        N_("show only names of changed files"),
 +                        DIFF_FORMAT_NAME, PARSE_OPT_NONEG),
 +              OPT_BIT_F(0, "name-status", &options->output_format,
 +                        N_("show only names and status of changed files"),
 +                        DIFF_FORMAT_NAME_STATUS, PARSE_OPT_NONEG),
 +              OPT_CALLBACK_F(0, "stat", options, N_("<width>[,<name-width>[,<count>]]"),
 +                             N_("generate diffstat"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_stat),
 +              OPT_CALLBACK_F(0, "stat-width", options, N_("<width>"),
 +                             N_("generate diffstat with a given width"),
 +                             PARSE_OPT_NONEG, diff_opt_stat),
 +              OPT_CALLBACK_F(0, "stat-name-width", options, N_("<width>"),
 +                             N_("generate diffstat with a given name width"),
 +                             PARSE_OPT_NONEG, diff_opt_stat),
 +              OPT_CALLBACK_F(0, "stat-graph-width", options, N_("<width>"),
 +                             N_("generate diffstat with a given graph width"),
 +                             PARSE_OPT_NONEG, diff_opt_stat),
 +              OPT_CALLBACK_F(0, "stat-count", options, N_("<count>"),
 +                             N_("generate diffstat with limited lines"),
 +                             PARSE_OPT_NONEG, diff_opt_stat),
 +              OPT_CALLBACK_F(0, "compact-summary", options, NULL,
 +                             N_("generate compact summary in diffstat"),
 +                             PARSE_OPT_NOARG, diff_opt_compact_summary),
 +              OPT_CALLBACK_F(0, "binary", options, NULL,
 +                             N_("output a binary diff that can be applied"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_binary),
 +              OPT_BOOL(0, "full-index", &options->flags.full_index,
 +                       N_("show full pre- and post-image object names on the \"index\" lines")),
 +              OPT_COLOR_FLAG(0, "color", &options->use_color,
 +                             N_("show colored diff")),
 +              OPT_CALLBACK_F(0, "ws-error-highlight", options, N_("<kind>"),
 +                             N_("highlight whitespace errors in the 'context', 'old' or 'new' lines in the diff"),
 +                             PARSE_OPT_NONEG, diff_opt_ws_error_highlight),
 +              OPT_SET_INT('z', NULL, &options->line_termination,
 +                          N_("do not munge pathnames and use NULs as output field terminators in --raw or --numstat"),
 +                          0),
 +              OPT__ABBREV(&options->abbrev),
 +              OPT_STRING_F(0, "src-prefix", &options->a_prefix, N_("<prefix>"),
 +                           N_("show the given source prefix instead of \"a/\""),
 +                           PARSE_OPT_NONEG),
 +              OPT_STRING_F(0, "dst-prefix", &options->b_prefix, N_("<prefix>"),
 +                           N_("show the given source prefix instead of \"b/\""),
 +                           PARSE_OPT_NONEG),
 +              OPT_CALLBACK_F(0, "line-prefix", options, N_("<prefix>"),
 +                             N_("prepend an additional prefix to every line of output"),
 +                             PARSE_OPT_NONEG, diff_opt_line_prefix),
 +              OPT_CALLBACK_F(0, "no-prefix", options, NULL,
 +                             N_("do not show any source or destination prefix"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_NOARG, diff_opt_no_prefix),
 +              OPT_INTEGER_F(0, "inter-hunk-context", &options->interhunkcontext,
 +                            N_("show context between diff hunks up to the specified number of lines"),
 +                            PARSE_OPT_NONEG),
 +              OPT_CALLBACK_F(0, "output-indicator-new",
 +                             &options->output_indicators[OUTPUT_INDICATOR_NEW],
 +                             N_("<char>"),
 +                             N_("specify the character to indicate a new line instead of '+'"),
 +                             PARSE_OPT_NONEG, diff_opt_char),
 +              OPT_CALLBACK_F(0, "output-indicator-old",
 +                             &options->output_indicators[OUTPUT_INDICATOR_OLD],
 +                             N_("<char>"),
 +                             N_("specify the character to indicate an old line instead of '-'"),
 +                             PARSE_OPT_NONEG, diff_opt_char),
 +              OPT_CALLBACK_F(0, "output-indicator-context",
 +                             &options->output_indicators[OUTPUT_INDICATOR_CONTEXT],
 +                             N_("<char>"),
 +                             N_("specify the character to indicate a context instead of ' '"),
 +                             PARSE_OPT_NONEG, diff_opt_char),
 +
 +              OPT_GROUP(N_("Diff rename options")),
 +              OPT_CALLBACK_F('B', "break-rewrites", &options->break_opt, N_("<n>[/<m>]"),
 +                             N_("break complete rewrite changes into pairs of delete and create"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 +                             diff_opt_break_rewrites),
 +              OPT_CALLBACK_F('M', "find-renames", options, N_("<n>"),
 +                             N_("detect renames"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 +                             diff_opt_find_renames),
 +              OPT_SET_INT_F('D', "irreversible-delete", &options->irreversible_delete,
 +                            N_("omit the preimage for deletes"),
 +                            1, PARSE_OPT_NONEG),
 +              OPT_CALLBACK_F('C', "find-copies", options, N_("<n>"),
 +                             N_("detect copies"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 +                             diff_opt_find_copies),
 +              OPT_BOOL(0, "find-copies-harder", &options->flags.find_copies_harder,
 +                       N_("use unmodified files as source to find copies")),
 +              OPT_SET_INT_F(0, "no-renames", &options->detect_rename,
 +                            N_("disable rename detection"),
 +                            0, PARSE_OPT_NONEG),
 +              OPT_BOOL(0, "rename-empty", &options->flags.rename_empty,
 +                       N_("use empty blobs as rename source")),
 +              OPT_CALLBACK_F(0, "follow", options, NULL,
 +                             N_("continue listing the history of a file beyond renames"),
 +                             PARSE_OPT_NOARG, diff_opt_follow),
 +              OPT_INTEGER('l', NULL, &options->rename_limit,
 +                          N_("prevent rename/copy detection if the number of rename/copy targets exceeds given limit")),
 +
 +              OPT_GROUP(N_("Diff algorithm options")),
 +              OPT_BIT(0, "minimal", &options->xdl_opts,
 +                      N_("produce the smallest possible diff"),
 +                      XDF_NEED_MINIMAL),
 +              OPT_BIT_F('w', "ignore-all-space", &options->xdl_opts,
 +                        N_("ignore whitespace when comparing lines"),
 +                        XDF_IGNORE_WHITESPACE, PARSE_OPT_NONEG),
 +              OPT_BIT_F('b', "ignore-space-change", &options->xdl_opts,
 +                        N_("ignore changes in amount of whitespace"),
 +                        XDF_IGNORE_WHITESPACE_CHANGE, PARSE_OPT_NONEG),
 +              OPT_BIT_F(0, "ignore-space-at-eol", &options->xdl_opts,
 +                        N_("ignore changes in whitespace at EOL"),
 +                        XDF_IGNORE_WHITESPACE_AT_EOL, PARSE_OPT_NONEG),
 +              OPT_BIT_F(0, "ignore-cr-at-eol", &options->xdl_opts,
 +                        N_("ignore carrier-return at the end of line"),
 +                        XDF_IGNORE_CR_AT_EOL, PARSE_OPT_NONEG),
 +              OPT_BIT_F(0, "ignore-blank-lines", &options->xdl_opts,
 +                        N_("ignore changes whose lines are all blank"),
 +                        XDF_IGNORE_BLANK_LINES, PARSE_OPT_NONEG),
 +              OPT_BIT(0, "indent-heuristic", &options->xdl_opts,
 +                      N_("heuristic to shift diff hunk boundaries for easy reading"),
 +                      XDF_INDENT_HEURISTIC),
 +              OPT_CALLBACK_F(0, "patience", options, NULL,
 +                             N_("generate diff using the \"patience diff\" algorithm"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_NOARG,
 +                             diff_opt_patience),
 +              OPT_BITOP(0, "histogram", &options->xdl_opts,
 +                        N_("generate diff using the \"histogram diff\" algorithm"),
 +                        XDF_HISTOGRAM_DIFF, XDF_DIFF_ALGORITHM_MASK),
 +              OPT_CALLBACK_F(0, "diff-algorithm", options, N_("<algorithm>"),
 +                             N_("choose a diff algorithm"),
 +                             PARSE_OPT_NONEG, diff_opt_diff_algorithm),
 +              OPT_CALLBACK_F(0, "anchored", options, N_("<text>"),
 +                             N_("generate diff using the \"anchored diff\" algorithm"),
 +                             PARSE_OPT_NONEG, diff_opt_anchored),
 +              OPT_CALLBACK_F(0, "word-diff", options, N_("<mode>"),
 +                             N_("show word diff, using <mode> to delimit changed words"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_word_diff),
 +              OPT_CALLBACK_F(0, "word-diff-regex", options, N_("<regex>"),
 +                             N_("use <regex> to decide what a word is"),
 +                             PARSE_OPT_NONEG, diff_opt_word_diff_regex),
 +              OPT_CALLBACK_F(0, "color-words", options, N_("<regex>"),
 +                             N_("equivalent to --word-diff=color --word-diff-regex=<regex>"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_color_words),
 +              OPT_CALLBACK_F(0, "color-moved", options, N_("<mode>"),
 +                             N_("move lines of code are colored differently"),
 +                             PARSE_OPT_OPTARG, diff_opt_color_moved),
 +              OPT_CALLBACK_F(0, "color-moved-ws", options, N_("<mode>"),
 +                             N_("how white spaces are ignored in --color-moved"),
 +                             0, diff_opt_color_moved_ws),
 +
 +              OPT_GROUP(N_("Diff other options")),
 +              OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
 +                             N_("when run from subdir, exclude changes outside and show relative paths"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 +                             diff_opt_relative),
 +              OPT_BOOL('a', "text", &options->flags.text,
 +                       N_("treat all files as text")),
 +              OPT_BOOL('R', NULL, &options->flags.reverse_diff,
 +                       N_("swap two inputs, reverse the diff")),
 +              OPT_BOOL(0, "exit-code", &options->flags.exit_with_status,
 +                       N_("exit with 1 if there were differences, 0 otherwise")),
 +              OPT_BOOL(0, "quiet", &options->flags.quick,
 +                       N_("disable all output of the program")),
 +              OPT_BOOL(0, "ext-diff", &options->flags.allow_external,
 +                       N_("allow an external diff helper to be executed")),
 +              OPT_CALLBACK_F(0, "textconv", options, NULL,
 +                             N_("run external text conversion filters when comparing binary files"),
 +                             PARSE_OPT_NOARG, diff_opt_textconv),
 +              OPT_CALLBACK_F(0, "ignore-submodules", options, N_("<when>"),
 +                             N_("ignore changes to submodules in the diff generation"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 +                             diff_opt_ignore_submodules),
 +              OPT_CALLBACK_F(0, "submodule", options, N_("<format>"),
 +                             N_("specify how differences in submodules are shown"),
 +                             PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
 +                             diff_opt_submodule),
 +              OPT_SET_INT_F(0, "ita-invisible-in-index", &options->ita_invisible_in_index,
 +                            N_("hide 'git add -N' entries from the index"),
 +                            1, PARSE_OPT_NONEG),
 +              OPT_SET_INT_F(0, "ita-visible-in-index", &options->ita_invisible_in_index,
 +                            N_("treat 'git add -N' entries as real in the index"),
 +                            0, PARSE_OPT_NONEG),
 +              OPT_CALLBACK_F('S', NULL, options, N_("<string>"),
 +                             N_("look for differences that change the number of occurrences of the specified string"),
 +                             0, diff_opt_pickaxe_string),
 +              OPT_CALLBACK_F('G', NULL, options, N_("<regex>"),
 +                             N_("look for differences that change the number of occurrences of the specified regex"),
 +                             0, diff_opt_pickaxe_regex),
 +              OPT_BIT_F(0, "pickaxe-all", &options->pickaxe_opts,
 +                        N_("show all changes in the changeset with -S or -G"),
 +                        DIFF_PICKAXE_ALL, PARSE_OPT_NONEG),
 +              OPT_BIT_F(0, "pickaxe-regex", &options->pickaxe_opts,
 +                        N_("treat <string> in -S as extended POSIX regular expression"),
 +                        DIFF_PICKAXE_REGEX, PARSE_OPT_NONEG),
 +              OPT_FILENAME('O', NULL, &options->orderfile,
 +                           N_("control the order in which files appear in the output")),
 +              OPT_CALLBACK_F(0, "find-object", options, N_("<object-id>"),
 +                             N_("look for differences that change the number of occurrences of the specified object"),
 +                             PARSE_OPT_NONEG, diff_opt_find_object),
 +              OPT_CALLBACK_F(0, "diff-filter", options, N_("[(A|C|D|M|R|T|U|X|B)...[*]]"),
 +                             N_("select files by diff type"),
 +                             PARSE_OPT_NONEG, diff_opt_diff_filter),
 +              { OPTION_CALLBACK, 0, "output", options, N_("<file>"),
 +                N_("Output to a specific file"),
 +                PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
 +
                OPT_END()
        };
  
  int diff_opt_parse(struct diff_options *options,
                   const char **av, int ac, const char *prefix)
  {
 -      const char *arg = av[0];
 -      const char *optarg;
 -      int argcount;
 -
        if (!prefix)
                prefix = "";
  
                           PARSE_OPT_ONE_SHOT |
                           PARSE_OPT_STOP_AT_NON_OPTION);
  
 -      if (ac)
 -              return ac;
 -
 -      /* Output format options */
 -      if (!strcmp(arg, "--patch-with-raw")) {
 -              enable_patch_output(&options->output_format);
 -              options->output_format |= DIFF_FORMAT_RAW;
 -      } else if (!strcmp(arg, "--numstat"))
 -              options->output_format |= DIFF_FORMAT_NUMSTAT;
 -      else if (!strcmp(arg, "--shortstat"))
 -              options->output_format |= DIFF_FORMAT_SHORTSTAT;
 -      else if (skip_prefix(arg, "-X", &arg) ||
 -               skip_to_optional_arg(arg, "--dirstat", &arg))
 -              return parse_dirstat_opt(options, arg);
 -      else if (!strcmp(arg, "--cumulative"))
 -              return parse_dirstat_opt(options, "cumulative");
 -      else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
 -              parse_dirstat_opt(options, "files");
 -              return parse_dirstat_opt(options, arg);
 -      }
 -      else if (!strcmp(arg, "--check"))
 -              options->output_format |= DIFF_FORMAT_CHECKDIFF;
 -      else if (!strcmp(arg, "--summary"))
 -              options->output_format |= DIFF_FORMAT_SUMMARY;
 -      else if (!strcmp(arg, "--patch-with-stat")) {
 -              enable_patch_output(&options->output_format);
 -              options->output_format |= DIFF_FORMAT_DIFFSTAT;
 -      } else if (!strcmp(arg, "--name-only"))
 -              options->output_format |= DIFF_FORMAT_NAME;
 -      else if (!strcmp(arg, "--name-status"))
 -              options->output_format |= DIFF_FORMAT_NAME_STATUS;
 -      else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
 -              options->output_format |= DIFF_FORMAT_NO_OUTPUT;
 -      else if (starts_with(arg, "--stat"))
 -              /* --stat, --stat-width, --stat-name-width, or --stat-count */
 -              return stat_opt(options, av);
 -      else if (!strcmp(arg, "--compact-summary")) {
 -               options->flags.stat_with_summary = 1;
 -               options->output_format |= DIFF_FORMAT_DIFFSTAT;
 -      } else if (!strcmp(arg, "--no-compact-summary"))
 -               options->flags.stat_with_summary = 0;
 -      else if (skip_prefix(arg, "--output-indicator-new=", &arg))
 -              options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
 -      else if (skip_prefix(arg, "--output-indicator-old=", &arg))
 -              options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
 -      else if (skip_prefix(arg, "--output-indicator-context=", &arg))
 -              options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
 -
 -      /* renames options */
 -      else if (starts_with(arg, "-B") ||
 -               skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
 -              if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
 -                      return error("invalid argument to -B: %s", arg+2);
 -      }
 -      else if (starts_with(arg, "-M") ||
 -               skip_to_optional_arg(arg, "--find-renames", NULL)) {
 -              if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
 -                      return error("invalid argument to -M: %s", arg+2);
 -              options->detect_rename = DIFF_DETECT_RENAME;
 -      }
 -      else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
 -              options->irreversible_delete = 1;
 -      }
 -      else if (starts_with(arg, "-C") ||
 -               skip_to_optional_arg(arg, "--find-copies", NULL)) {
 -              if (options->detect_rename == DIFF_DETECT_COPY)
 -                      options->flags.find_copies_harder = 1;
 -              if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
 -                      return error("invalid argument to -C: %s", arg+2);
 -              options->detect_rename = DIFF_DETECT_COPY;
 -      }
 -      else if (!strcmp(arg, "--no-renames"))
 -              options->detect_rename = 0;
 -      else if (!strcmp(arg, "--rename-empty"))
 -              options->flags.rename_empty = 1;
 -      else if (!strcmp(arg, "--no-rename-empty"))
 -              options->flags.rename_empty = 0;
 -      else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
 -              options->flags.relative_name = 1;
 -              if (arg)
 -                      options->prefix = arg;
 -      }
 -
 -      /* xdiff options */
 -      else if (!strcmp(arg, "--minimal"))
 -              DIFF_XDL_SET(options, NEED_MINIMAL);
 -      else if (!strcmp(arg, "--no-minimal"))
 -              DIFF_XDL_CLR(options, NEED_MINIMAL);
 -      else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
 -              DIFF_XDL_SET(options, IGNORE_WHITESPACE);
 -      else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
 -              DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
 -      else if (!strcmp(arg, "--ignore-space-at-eol"))
 -              DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
 -      else if (!strcmp(arg, "--ignore-cr-at-eol"))
 -              DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
 -      else if (!strcmp(arg, "--ignore-blank-lines"))
 -              DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
 -      else if (!strcmp(arg, "--indent-heuristic"))
 -              DIFF_XDL_SET(options, INDENT_HEURISTIC);
 -      else if (!strcmp(arg, "--no-indent-heuristic"))
 -              DIFF_XDL_CLR(options, INDENT_HEURISTIC);
 -      else if (!strcmp(arg, "--patience")) {
 -              int i;
 -              options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
 -              /*
 -               * Both --patience and --anchored use PATIENCE_DIFF
 -               * internally, so remove any anchors previously
 -               * specified.
 -               */
 -              for (i = 0; i < options->anchors_nr; i++)
 -                      free(options->anchors[i]);
 -              options->anchors_nr = 0;
 -      } else if (!strcmp(arg, "--histogram"))
 -              options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
 -      else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
 -              long value = parse_algorithm_value(optarg);
 -              if (value < 0)
 -                      return error("option diff-algorithm accepts \"myers\", "
 -                                   "\"minimal\", \"patience\" and \"histogram\"");
 -              /* clear out previous settings */
 -              DIFF_XDL_CLR(options, NEED_MINIMAL);
 -              options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
 -              options->xdl_opts |= value;
 -              return argcount;
 -      } else if (skip_prefix(arg, "--anchored=", &arg)) {
 -              options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
 -              ALLOC_GROW(options->anchors, options->anchors_nr + 1,
 -                         options->anchors_alloc);
 -              options->anchors[options->anchors_nr++] = xstrdup(arg);
 -      }
 -
 -      /* flags options */
 -      else if (!strcmp(arg, "--binary")) {
 -              enable_patch_output(&options->output_format);
 -              options->flags.binary = 1;
 -      }
 -      else if (!strcmp(arg, "--full-index"))
 -              options->flags.full_index = 1;
 -      else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
 -              options->flags.text = 1;
 -      else if (!strcmp(arg, "-R"))
 -              options->flags.reverse_diff = 1;
 -      else if (!strcmp(arg, "--find-copies-harder"))
 -              options->flags.find_copies_harder = 1;
 -      else if (!strcmp(arg, "--follow"))
 -              options->flags.follow_renames = 1;
 -      else if (!strcmp(arg, "--no-follow")) {
 -              options->flags.follow_renames = 0;
 -              options->flags.default_follow_renames = 0;
 -      } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
 -              int value = git_config_colorbool(NULL, arg);
 -              if (value < 0)
 -                      return error("option `color' expects \"always\", \"auto\", or \"never\"");
 -              options->use_color = value;
 -      }
 -      else if (!strcmp(arg, "--no-color"))
 -              options->use_color = 0;
 -      else if (!strcmp(arg, "--color-moved")) {
 -              if (diff_color_moved_default)
 -                      options->color_moved = diff_color_moved_default;
 -              if (options->color_moved == COLOR_MOVED_NO)
 -                      options->color_moved = COLOR_MOVED_DEFAULT;
 -      } else if (!strcmp(arg, "--no-color-moved"))
 -              options->color_moved = COLOR_MOVED_NO;
 -      else if (skip_prefix(arg, "--color-moved=", &arg)) {
 -              int cm = parse_color_moved(arg);
 -              if (cm < 0)
 -                      return error("bad --color-moved argument: %s", arg);
 -              options->color_moved = cm;
 -      } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
 -              unsigned cm = parse_color_moved_ws(arg);
 -              if (cm & COLOR_MOVED_WS_ERROR)
 -                      return -1;
 -              options->color_moved_ws_handling = cm;
 -      } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
 -              options->use_color = 1;
 -              options->word_diff = DIFF_WORDS_COLOR;
 -      }
 -      else if (!strcmp(arg, "--word-diff")) {
 -              if (options->word_diff == DIFF_WORDS_NONE)
 -                      options->word_diff = DIFF_WORDS_PLAIN;
 -      }
 -      else if (skip_prefix(arg, "--word-diff=", &arg)) {
 -              if (!strcmp(arg, "plain"))
 -                      options->word_diff = DIFF_WORDS_PLAIN;
 -              else if (!strcmp(arg, "color")) {
 -                      options->use_color = 1;
 -                      options->word_diff = DIFF_WORDS_COLOR;
 -              }
 -              else if (!strcmp(arg, "porcelain"))
 -                      options->word_diff = DIFF_WORDS_PORCELAIN;
 -              else if (!strcmp(arg, "none"))
 -                      options->word_diff = DIFF_WORDS_NONE;
 -              else
 -                      die("bad --word-diff argument: %s", arg);
 -      }
 -      else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
 -              if (options->word_diff == DIFF_WORDS_NONE)
 -                      options->word_diff = DIFF_WORDS_PLAIN;
 -              options->word_regex = optarg;
 -              return argcount;
 -      }
 -      else if (!strcmp(arg, "--exit-code"))
 -              options->flags.exit_with_status = 1;
 -      else if (!strcmp(arg, "--quiet"))
 -              options->flags.quick = 1;
 -      else if (!strcmp(arg, "--ext-diff"))
 -              options->flags.allow_external = 1;
 -      else if (!strcmp(arg, "--no-ext-diff"))
 -              options->flags.allow_external = 0;
 -      else if (!strcmp(arg, "--textconv")) {
 -              options->flags.allow_textconv = 1;
 -              options->flags.textconv_set_via_cmdline = 1;
 -      } else if (!strcmp(arg, "--no-textconv"))
 -              options->flags.allow_textconv = 0;
 -      else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
 -              options->flags.override_submodule_config = 1;
 -              handle_ignore_submodules_arg(options, arg);
 -      } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
 -              return parse_submodule_opt(options, arg);
 -      else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
 -              return parse_ws_error_highlight_opt(options, arg);
 -      else if (!strcmp(arg, "--ita-invisible-in-index"))
 -              options->ita_invisible_in_index = 1;
 -      else if (!strcmp(arg, "--ita-visible-in-index"))
 -              options->ita_invisible_in_index = 0;
 -
 -      /* misc options */
 -      else if (!strcmp(arg, "-z"))
 -              options->line_termination = 0;
 -      else if ((argcount = short_opt('l', av, &optarg))) {
 -              options->rename_limit = strtoul(optarg, NULL, 10);
 -              return argcount;
 -      }
 -      else if ((argcount = short_opt('S', av, &optarg))) {
 -              options->pickaxe = optarg;
 -              options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
 -              return argcount;
 -      } else if ((argcount = short_opt('G', av, &optarg))) {
 -              options->pickaxe = optarg;
 -              options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
 -              return argcount;
 -      }
 -      else if (!strcmp(arg, "--pickaxe-all"))
 -              options->pickaxe_opts |= DIFF_PICKAXE_ALL;
 -      else if (!strcmp(arg, "--pickaxe-regex"))
 -              options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
 -      else if ((argcount = short_opt('O', av, &optarg))) {
 -              options->orderfile = prefix_filename(prefix, optarg);
 -              return argcount;
 -      } else if (skip_prefix(arg, "--find-object=", &arg))
 -              return parse_objfind_opt(options, arg);
 -      else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
 -              int offending = parse_diff_filter_opt(optarg, options);
 -              if (offending)
 -                      die("unknown change class '%c' in --diff-filter=%s",
 -                          offending, optarg);
 -              return argcount;
 -      }
 -      else if (!strcmp(arg, "--no-abbrev"))
 -              options->abbrev = 0;
 -      else if (!strcmp(arg, "--abbrev"))
 -              options->abbrev = DEFAULT_ABBREV;
 -      else if (skip_prefix(arg, "--abbrev=", &arg)) {
 -              options->abbrev = strtoul(arg, NULL, 10);
 -              if (options->abbrev < MINIMUM_ABBREV)
 -                      options->abbrev = MINIMUM_ABBREV;
 -              else if (the_hash_algo->hexsz < options->abbrev)
 -                      options->abbrev = the_hash_algo->hexsz;
 -      }
 -      else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
 -              options->a_prefix = optarg;
 -              return argcount;
 -      }
 -      else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
 -              options->line_prefix = optarg;
 -              options->line_prefix_length = strlen(options->line_prefix);
 -              graph_setup_line_prefix(options);
 -              return argcount;
 -      }
 -      else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
 -              options->b_prefix = optarg;
 -              return argcount;
 -      }
 -      else if (!strcmp(arg, "--no-prefix"))
 -              options->a_prefix = options->b_prefix = "";
 -      else if (opt_arg(arg, '\0', "inter-hunk-context",
 -                       &options->interhunkcontext))
 -              ;
 -      else if ((argcount = parse_long_opt("output", av, &optarg))) {
 -              char *path = prefix_filename(prefix, optarg);
 -              options->file = xfopen(path, "w");
 -              options->close_file = 1;
 -              if (options->use_color != GIT_COLOR_ALWAYS)
 -                      options->use_color = GIT_COLOR_NEVER;
 -              free(path);
 -              return argcount;
 -      } else
 -              return 0;
 -      return 1;
 +      return ac;
  }
  
  int parse_rename_score(const char **cp_p)
        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
  }
  
 -static int diff_scoreopt_parse(const char *opt)
 -{
 -      int opt1, opt2, cmd;
 -
 -      if (*opt++ != '-')
 -              return -1;
 -      cmd = *opt++;
 -      if (cmd == '-') {
 -              /* convert the long-form arguments into short-form versions */
 -              if (skip_prefix(opt, "break-rewrites", &opt)) {
 -                      if (*opt == 0 || *opt++ == '=')
 -                              cmd = 'B';
 -              } else if (skip_prefix(opt, "find-copies", &opt)) {
 -                      if (*opt == 0 || *opt++ == '=')
 -                              cmd = 'C';
 -              } else if (skip_prefix(opt, "find-renames", &opt)) {
 -                      if (*opt == 0 || *opt++ == '=')
 -                              cmd = 'M';
 -              }
 -      }
 -      if (cmd != 'M' && cmd != 'C' && cmd != 'B')
 -              return -1; /* that is not a -M, -C, or -B option */
 -
 -      opt1 = parse_rename_score(&opt);
 -      if (cmd != 'B')
 -              opt2 = 0;
 -      else {
 -              if (*opt == 0)
 -                      opt2 = 0;
 -              else if (*opt != '/')
 -                      return -1; /* we expect -B80/99 or -B80 */
 -              else {
 -                      opt++;
 -                      opt2 = parse_rename_score(&opt);
 -              }
 -      }
 -      if (*opt != 0)
 -              return -1;
 -      return opt1 | (opt2 << 16);
 -}
 -
  struct diff_queue_struct diff_queued_diff;
  
  void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
@@@ -6210,10 -5943,8 +6212,10 @@@ static void diff_flush_patch_all_file_p
  
                for (i = 0; i < esm.nr; i++)
                        free((void *)esm.buf[i].line);
 +              esm.nr = 0;
 +
 +              o->emitted_symbols = NULL;
        }
 -      esm.nr = 0;
  }
  
  void diff_flush(struct diff_options *options)
@@@ -6472,47 -6203,14 +6474,47 @@@ static int diffnamecmp(const void *a_, 
        return strcmp(name_a, name_b);
  }
  
 -void diffcore_fix_diff_index(struct diff_options *options)
 +void diffcore_fix_diff_index(void)
  {
        struct diff_queue_struct *q = &diff_queued_diff;
        QSORT(q->queue, q->nr, diffnamecmp);
  }
  
 +static void add_if_missing(struct repository *r,
 +                         struct oid_array *to_fetch,
 +                         const struct diff_filespec *filespec)
 +{
 +      if (filespec && filespec->oid_valid &&
 +          oid_object_info_extended(r, &filespec->oid, NULL,
 +                                   OBJECT_INFO_FOR_PREFETCH))
 +              oid_array_append(to_fetch, &filespec->oid);
 +}
 +
  void diffcore_std(struct diff_options *options)
  {
 +      if (options->repo == the_repository &&
 +          repository_format_partial_clone) {
 +              /*
 +               * Prefetch the diff pairs that are about to be flushed.
 +               */
 +              int i;
 +              struct diff_queue_struct *q = &diff_queued_diff;
 +              struct oid_array to_fetch = OID_ARRAY_INIT;
 +
 +              for (i = 0; i < q->nr; i++) {
 +                      struct diff_filepair *p = q->queue[i];
 +                      add_if_missing(options->repo, &to_fetch, p->one);
 +                      add_if_missing(options->repo, &to_fetch, p->two);
 +              }
 +              if (to_fetch.nr)
 +                      /*
 +                       * NEEDSWORK: Consider deduplicating the OIDs sent.
 +                       */
 +                      fetch_objects(repository_format_partial_clone,
 +                                    to_fetch.oid, to_fetch.nr);
 +              oid_array_clear(&to_fetch);
 +      }
 +
        /* NOTE please keep the following in sync with diff_tree_combined() */
        if (options->skip_stat_unmatch)
                diffcore_skip_stat_unmatch(options);
diff --combined diff.h
index b20cbcc0914250de4921310d16d58ada4acb7984,7b66bf1b80c115620d22b4e8eacea0a4c0ea11d8..d5e44baa9640d2917c69ad3463be0228288b98e4
--- 1/diff.h
--- 2/diff.h
+++ b/diff.h
@@@ -169,7 -169,7 +169,7 @@@ struct diff_options 
        const char *prefix;
        int prefix_length;
        const char *stat_sep;
-       long xdl_opts;
+       int xdl_opts;
  
        /* see Documentation/diff-options.txt */
        char **anchors;
        struct option *parseopts;
  };
  
 +unsigned diff_filter_bit(char status);
 +
  void diff_emit_submodule_del(struct diff_options *o, const char *line);
  void diff_emit_submodule_add(struct diff_options *o, const char *line);
  void diff_emit_submodule_untracked(struct diff_options *o, const char *path);
@@@ -298,7 -296,6 +298,7 @@@ struct combine_diff_path 
                char status;
                unsigned int mode;
                struct object_id oid;
 +              struct strbuf path;
        } parent[FLEX_ARRAY];
  };
  #define combine_diff_path_size(n, l) \
@@@ -372,7 -369,7 +372,7 @@@ int git_config_rename(const char *var, 
  #define DIFF_PICKAXE_IGNORE_CASE      32
  
  void diffcore_std(struct diff_options *);
 -void diffcore_fix_diff_index(struct diff_options *);
 +void diffcore_fix_diff_index(void);
  
  #define COMMON_DIFF_OPTIONS_HELP \
  "\ncommon diff options:\n" \
@@@ -440,8 -437,7 +440,8 @@@ int diff_flush_patch_id(struct diff_opt
  
  int diff_result_code(struct diff_options *, int);
  
 -void diff_no_index(struct repository *, struct rev_info *, int, const char **);
 +int diff_no_index(struct rev_info *,
 +                int implicit_no_index, int, const char **);
  
  int index_differs_from(struct repository *r, const char *def,
                       const struct diff_flags *flags,
diff --combined parse-options-cb.c
index 4b95d04a37c028322c6fbf7d3f1b59e0d541fdb3,02293493b01a5a9e91c54da9833a583ea1c643b3..a3de795c581a3aab084efac75ed2d6edc2535a15
@@@ -16,14 -16,17 +16,17 @@@ int parse_opt_abbrev_cb(const struct op
        if (!arg) {
                v = unset ? 0 : DEFAULT_ABBREV;
        } else {
+               if (!*arg)
+                       return error(_("option `%s' expects a numerical value"),
+                                    opt->long_name);
                v = strtol(arg, (char **)&arg, 10);
                if (*arg)
                        return error(_("option `%s' expects a numerical value"),
                                     opt->long_name);
                if (v && v < MINIMUM_ABBREV)
                        v = MINIMUM_ABBREV;
 -              else if (v > 40)
 -                      v = 40;
 +              else if (v > the_hash_algo->hexsz)
 +                      v = the_hash_algo->hexsz;
        }
        *(int *)(opt->value) = v;
        return 0;
@@@ -96,23 -99,6 +99,23 @@@ int parse_opt_commits(const struct opti
        return 0;
  }
  
 +int parse_opt_commit(const struct option *opt, const char *arg, int unset)
 +{
 +      struct object_id oid;
 +      struct commit *commit;
 +      struct commit **target = opt->value;
 +
 +      if (!arg)
 +              return -1;
 +      if (get_oid(arg, &oid))
 +              return error("malformed object name %s", arg);
 +      commit = lookup_commit_reference(the_repository, &oid);
 +      if (!commit)
 +              return error("no such commit %s", arg);
 +      *target = commit;
 +      return 0;
 +}
 +
  int parse_opt_object_name(const struct option *opt, const char *arg, int unset)
  {
        struct object_id oid;
        return 0;
  }
  
 +int parse_opt_object_id(const struct option *opt, const char *arg, int unset)
 +{
 +      struct object_id oid;
 +      struct object_id *target = opt->value;
 +
 +      if (unset) {
 +              *target = null_oid;
 +              return 0;
 +      }
 +      if (!arg)
 +              return -1;
 +      if (get_oid(arg, &oid))
 +              return error(_("malformed object name '%s'"), arg);
 +      *target = oid;
 +      return 0;
 +}
 +
  int parse_opt_tertiary(const struct option *opt, const char *arg, int unset)
  {
        int *target = opt->value;
diff --combined parse-options.c
index 987e27cb91162ab03320ff9674f3ad52ffa829b4,c8ee2211969219b693b68c56f0fefa11aaf10bb0..87b26a1d922e8905fe369b164ae5cad7ea372426
@@@ -6,8 -6,6 +6,8 @@@
  #include "color.h"
  #include "utf8.h"
  
 +static int disallow_abbreviated_options;
 +
  #define OPT_SHORT 1
  #define OPT_UNSET 2
  
@@@ -195,6 -193,9 +195,9 @@@ static enum parse_opt_result get_value(
                }
                if (get_arg(p, opt, flags, &arg))
                        return -1;
+               if (!*arg)
+                       return error(_("%s expects a numerical value"),
+                                    optname(opt, flags));
                *(int *)opt->value = strtol(arg, (char **)&s, 10);
                if (*s)
                        return error(_("%s expects a numerical value"),
@@@ -261,35 -262,6 +264,35 @@@ static enum parse_opt_result parse_shor
        return PARSE_OPT_UNKNOWN;
  }
  
 +static int has_string(const char *it, const char **array)
 +{
 +      while (*array)
 +              if (!strcmp(it, *(array++)))
 +                      return 1;
 +      return 0;
 +}
 +
 +static int is_alias(struct parse_opt_ctx_t *ctx,
 +                  const struct option *one_opt,
 +                  const struct option *another_opt)
 +{
 +      const char **group;
 +
 +      if (!ctx->alias_groups)
 +              return 0;
 +
 +      if (!one_opt->long_name || !another_opt->long_name)
 +              return 0;
 +
 +      for (group = ctx->alias_groups; *group; group += 3) {
 +              /* it and other are from the same family? */
 +              if (has_string(one_opt->long_name, group) &&
 +                  has_string(another_opt->long_name, group))
 +                      return 1;
 +      }
 +      return 0;
 +}
 +
  static enum parse_opt_result parse_long_opt(
        struct parse_opt_ctx_t *p, const char *arg,
        const struct option *options)
@@@ -317,8 -289,6 +320,8 @@@ again
                                             optname(options, flags));
                        if (*rest)
                                continue;
 +                      if (options->value)
 +                              *(int *)options->value = options->defval;
                        p->out[p->cpidx++] = arg - 2;
                        return PARSE_OPT_DONE;
                }
                        if (!(p->flags & PARSE_OPT_KEEP_UNKNOWN) &&
                            !strncmp(long_name, arg, arg_end - arg)) {
  is_abbreviated:
 -                              if (abbrev_option) {
 +                              if (abbrev_option &&
 +                                  !is_alias(p, abbrev_option, options)) {
                                        /*
                                         * If this is abbreviated, it is
                                         * ambiguous. So when there is no
                return get_value(p, options, all_opts, flags ^ opt_flags);
        }
  
 +      if (disallow_abbreviated_options && (ambiguous_option || abbrev_option))
 +              die("disallowed abbreviated or ambiguous option '%.*s'",
 +                  (int)(arg_end - arg), arg);
 +
        if (ambiguous_option) {
                error(_("ambiguous option: %s "
                        "(could be --%s%s or --%s%s)"),
@@@ -477,10 -442,6 +480,10 @@@ static void parse_options_check(const s
                        if (opts->callback)
                                BUG("OPTION_LOWLEVEL_CALLBACK needs no high level callback");
                        break;
 +              case OPTION_ALIAS:
 +                      BUG("OPT_ALIAS() should not remain at this point. "
 +                          "Are you using parse_options_step() directly?\n"
 +                          "That case is not supported yet.");
                default:
                        ; /* ok. (usually accepts an argument) */
                }
                exit(128);
  }
  
 -void parse_options_start(struct parse_opt_ctx_t *ctx,
 -                       int argc, const char **argv, const char *prefix,
 -                       const struct option *options, int flags)
 +static void parse_options_start_1(struct parse_opt_ctx_t *ctx,
 +                                int argc, const char **argv, const char *prefix,
 +                                const struct option *options, int flags)
  {
 -      memset(ctx, 0, sizeof(*ctx));
        ctx->argc = argc;
        ctx->argv = argv;
        if (!(flags & PARSE_OPT_ONE_SHOT)) {
        parse_options_check(options);
  }
  
 +void parse_options_start(struct parse_opt_ctx_t *ctx,
 +                       int argc, const char **argv, const char *prefix,
 +                       const struct option *options, int flags)
 +{
 +      memset(ctx, 0, sizeof(*ctx));
 +      parse_options_start_1(ctx, argc, argv, prefix, options, flags);
 +}
 +
  static void show_negated_gitcomp(const struct option *opts, int nr_noopts)
  {
        int printed_dashdash = 0;
        }
  }
  
 -static int show_gitcomp(struct parse_opt_ctx_t *ctx,
 -                      const struct option *opts)
 +static int show_gitcomp(const struct option *opts)
  {
        const struct option *original_opts = opts;
        int nr_noopts = 0;
        return PARSE_OPT_COMPLETE;
  }
  
 +/*
 + * Scan and may produce a new option[] array, which should be used
 + * instead of the original 'options'.
 + *
 + * Right now this is only used to preprocess and substitue
 + * OPTION_ALIAS.
 + */
 +static struct option *preprocess_options(struct parse_opt_ctx_t *ctx,
 +                                       const struct option *options)
 +{
 +      struct option *newopt;
 +      int i, nr, alias;
 +      int nr_aliases = 0;
 +
 +      for (nr = 0; options[nr].type != OPTION_END; nr++) {
 +              if (options[nr].type == OPTION_ALIAS)
 +                      nr_aliases++;
 +      }
 +
 +      if (!nr_aliases)
 +              return NULL;
 +
 +      ALLOC_ARRAY(newopt, nr + 1);
 +      COPY_ARRAY(newopt, options, nr + 1);
 +
 +      /* each alias has two string pointers and NULL */
 +      CALLOC_ARRAY(ctx->alias_groups, 3 * (nr_aliases + 1));
 +
 +      for (alias = 0, i = 0; i < nr; i++) {
 +              int short_name;
 +              const char *long_name;
 +              const char *source;
 +              int j;
 +
 +              if (newopt[i].type != OPTION_ALIAS)
 +                      continue;
 +
 +              short_name = newopt[i].short_name;
 +              long_name = newopt[i].long_name;
 +              source = newopt[i].value;
 +
 +              if (!long_name)
 +                      BUG("An alias must have long option name");
 +
 +              for (j = 0; j < nr; j++) {
 +                      const char *name = options[j].long_name;
 +
 +                      if (!name || strcmp(name, source))
 +                              continue;
 +
 +                      if (options[j].type == OPTION_ALIAS)
 +                              BUG("No please. Nested aliases are not supported.");
 +
 +                      /*
 +                       * NEEDSWORK: this is a bit inconsistent because
 +                       * usage_with_options() on the original options[] will print
 +                       * help string as "alias of %s" but "git cmd -h" will
 +                       * print the original help string.
 +                       */
 +                      memcpy(newopt + i, options + j, sizeof(*newopt));
 +                      newopt[i].short_name = short_name;
 +                      newopt[i].long_name = long_name;
 +                      break;
 +              }
 +
 +              if (j == nr)
 +                      BUG("could not find source option '%s' of alias '%s'",
 +                          source, newopt[i].long_name);
 +              ctx->alias_groups[alias * 3 + 0] = newopt[i].long_name;
 +              ctx->alias_groups[alias * 3 + 1] = options[j].long_name;
 +              ctx->alias_groups[alias * 3 + 2] = NULL;
 +              alias++;
 +      }
 +
 +      return newopt;
 +}
 +
  static int usage_with_options_internal(struct parse_opt_ctx_t *,
                                       const char * const *,
                                       const struct option *, int, int);
@@@ -728,7 -606,7 +731,7 @@@ int parse_options_step(struct parse_opt
  
                /* lone --git-completion-helper is asked by git-completion.bash */
                if (ctx->total == 1 && !strcmp(arg + 1, "-git-completion-helper"))
 -                      return show_gitcomp(ctx, options);
 +                      return show_gitcomp(options);
  
                if (arg[1] != '-') {
                        ctx->opt = arg + 1;
@@@ -832,16 -710,8 +835,16 @@@ int parse_options(int argc, const char 
                  int flags)
  {
        struct parse_opt_ctx_t ctx;
 +      struct option *real_options;
  
 -      parse_options_start(&ctx, argc, argv, prefix, options, flags);
 +      disallow_abbreviated_options =
 +              git_env_bool("GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS", 0);
 +
 +      memset(&ctx, 0, sizeof(ctx));
 +      real_options = preprocess_options(&ctx, options);
 +      if (real_options)
 +              options = real_options;
 +      parse_options_start_1(&ctx, argc, argv, prefix, options, flags);
        switch (parse_options_step(&ctx, options, usagestr)) {
        case PARSE_OPT_HELP:
        case PARSE_OPT_ERROR:
        }
  
        precompose_argv(argc, argv);
 +      free(real_options);
 +      free(ctx.alias_groups);
        return parse_options_end(&ctx);
  }
  
@@@ -960,12 -828,6 +963,12 @@@ static int usage_with_options_internal(
                        fputc('\n', outfile);
                        pad = USAGE_OPTS_WIDTH;
                }
 +              if (opts->type == OPTION_ALIAS) {
 +                      fprintf(outfile, "%*s", pad + USAGE_GAP, "");
 +                      fprintf_ln(outfile, _("alias of --%s"),
 +                                 (const char *)opts->value);
 +                      continue;
 +              }
                fprintf(outfile, "%*s%s\n", pad + USAGE_GAP, "", _(opts->help));
        }
        fputc('\n', outfile);
diff --combined t/t4013-diff-various.sh
index 9f8f0e84ad4f35b72da73ef8ddfee0a3cddfbe1a,3c4a3dfcc1ae717d0b7e8cd7819780fe7d832d32..a9054d2db11608d7ae2d407e9422a4f61c5e9afd
@@@ -98,12 -98,6 +98,12 @@@ test_expect_success setup 
        git commit -m "update mode" &&
        git checkout -f master &&
  
 +      # Same merge as master, but with parents reversed. Hide it in a
 +      # pseudo-ref to avoid impacting tests with --all.
 +      commit=$(echo reverse |
 +               git commit-tree -p master^2 -p master^1 master^{tree}) &&
 +      git update-ref REVERSE $commit &&
 +
        git config diff.renames false &&
  
        git show-branch
@@@ -245,8 -239,6 +245,8 @@@ diff-tree --cc --stat --summary maste
  # stat summary should show the diffstat and summary with the first parent
  diff-tree -c --stat --summary side
  diff-tree --cc --stat --summary side
 +diff-tree --cc --shortstat master
 +diff-tree --cc --summary REVERSE
  # improved by Timo's patch
  diff-tree --cc --patch-with-stat master
  # improved by Timo's patch
@@@ -338,6 -330,8 +338,8 @@@ format-patch --inline --stdout initial.
  format-patch --stdout --cover-letter -n initial..master^
  
  diff --abbrev initial..side
+ diff -U initial..side
+ diff -U1 initial..side
  diff -r initial..side
  diff --stat initial..side
  diff -r --stat initial..side
@@@ -358,7 -352,6 +360,7 @@@ diff --line-prefix=abc master master^ s
  diff --dirstat master~1 master~2
  diff --dirstat initial rearrange
  diff --dirstat-by-file initial rearrange
 +diff --dirstat --cc master~1 master
  # No-index --abbrev and --no-abbrev
  diff --raw initial
  :noellipses diff --raw initial