Merge branch 'kb/diff-C-M-synonym'

* kb/diff-C-M-synonym:
  diff: use "find" instead of "detect" as prefix for long forms of -M and -C
  diff: add --detect-copies-harder as a synonym for --find-copies-harder

diff --combined diff.c
index 6991ed4e17343a3104d3fd518b5d85d0913e9259,b5ef1ec55e2d6a97ab00d5692a93affb66803a31..0a438694351e555f66cbb3d24759d3a10a46ff20
--- 1/diff.c
--- 2/diff.c
+++ b/diff.c
@@@ -2158,7 -2158,7 +2158,7 @@@ static void builtin_checkdiff(const cha
  
                        ecbdata.ws_rule = data.ws_rule;
                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
 -                      blank_at_eof = ecbdata.blank_at_eof_in_preimage;
 +                      blank_at_eof = ecbdata.blank_at_eof_in_postimage;
  
                        if (blank_at_eof) {
                                static char *err;
@@@ -2391,14 -2391,10 +2391,14 @@@ int diff_populate_filespec(struct diff_
        }
        else {
                enum object_type type;
 -              if (size_only)
 +              if (size_only) {
                        type = sha1_object_info(s->sha1, &s->size);
 -              else {
 +                      if (type < 0)
 +                              die("unable to read %s", sha1_to_hex(s->sha1));
 +              } else {
                        s->data = read_sha1_file(s->sha1, &type, &s->size);
 +                      if (!s->data)
 +                              die("unable to read %s", sha1_to_hex(s->sha1));
                        s->should_free = 1;
                }
        }
@@@ -3152,20 -3148,20 +3152,20 @@@ int diff_opt_parse(struct diff_options 
        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
                 !strcmp(arg, "--break-rewrites")) {
                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
 -                      return -1;
 +                      return error("invalid argument to -B: %s", arg+2);
        }
-       else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--detect-renames=") ||
-                !strcmp(arg, "--detect-renames")) {
+       else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
+                !strcmp(arg, "--find-renames")) {
                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
 -                      return -1;
 +                      return error("invalid argument to -M: %s", arg+2);
                options->detect_rename = DIFF_DETECT_RENAME;
        }
-       else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--detect-copies=") ||
-                !strcmp(arg, "--detect-copies")) {
+       else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
+                !strcmp(arg, "--find-copies")) {
                if (options->detect_rename == DIFF_DETECT_COPY)
                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
 -                      return -1;
 +                      return error("invalid argument to -C: %s", arg+2);
                options->detect_rename = DIFF_DETECT_COPY;
        }
        else if (!strcmp(arg, "--no-renames"))
@@@ -3384,12 -3380,12 +3384,12 @@@ static int diff_scoreopt_parse(const ch
                        opt += strlen("break-rewrites");
                        if (*opt == 0 || *opt++ == '=')
                                cmd = 'B';
-               } else if (!prefixcmp(opt, "detect-copies")) {
-                       opt += strlen("detect-copies");
+               } else if (!prefixcmp(opt, "find-copies")) {
+                       opt += strlen("find-copies");
                        if (*opt == 0 || *opt++ == '=')
                                cmd = 'C';
-               } else if (!prefixcmp(opt, "detect-renames")) {
-                       opt += strlen("detect-renames");
+               } else if (!prefixcmp(opt, "find-renames")) {
+                       opt += strlen("find-renames");
                        if (*opt == 0 || *opt++ == '=')
                                cmd = 'M';
                }