git-p4: map a P4 user to Git author name and email address
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index 3f1f08f9fd28173e10440c8436d57c14215c342c..059123c5dcef4129763895b0f2ad5a54728b0c07 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -2,6 +2,7 @@
  * Copyright (C) 2005 Junio C Hamano
  */
 #include "cache.h"
+#include "tempfile.h"
 #include "quote.h"
 #include "diff.h"
 #include "diffcore.h"
@@ -12,7 +13,7 @@
 #include "run-command.h"
 #include "utf8.h"
 #include "userdiff.h"
-#include "sigchain.h"
+#include "submodule-config.h"
 #include "submodule.h"
 #include "ll-merge.h"
 #include "string-list.h"
@@ -42,7 +43,7 @@ static long diff_algorithm;
 
 static char diff_colors[][COLOR_MAXLEN] = {
        GIT_COLOR_RESET,
-       GIT_COLOR_NORMAL,       /* PLAIN */
+       GIT_COLOR_NORMAL,       /* CONTEXT */
        GIT_COLOR_BOLD,         /* METAINFO */
        GIT_COLOR_CYAN,         /* FRAGINFO */
        GIT_COLOR_RED,          /* OLD */
@@ -52,23 +53,23 @@ static char diff_colors[][COLOR_MAXLEN] = {
        GIT_COLOR_NORMAL,       /* FUNCINFO */
 };
 
-static int parse_diff_color_slot(const char *var, int ofs)
+static int parse_diff_color_slot(const char *var)
 {
-       if (!strcasecmp(var+ofs, "plain"))
-               return DIFF_PLAIN;
-       if (!strcasecmp(var+ofs, "meta"))
+       if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
+               return DIFF_CONTEXT;
+       if (!strcasecmp(var, "meta"))
                return DIFF_METAINFO;
-       if (!strcasecmp(var+ofs, "frag"))
+       if (!strcasecmp(var, "frag"))
                return DIFF_FRAGINFO;
-       if (!strcasecmp(var+ofs, "old"))
+       if (!strcasecmp(var, "old"))
                return DIFF_FILE_OLD;
-       if (!strcasecmp(var+ofs, "new"))
+       if (!strcasecmp(var, "new"))
                return DIFF_FILE_NEW;
-       if (!strcasecmp(var+ofs, "commit"))
+       if (!strcasecmp(var, "commit"))
                return DIFF_COMMIT;
-       if (!strcasecmp(var+ofs, "whitespace"))
+       if (!strcasecmp(var, "whitespace"))
                return DIFF_WHITESPACE;
-       if (!strcasecmp(var+ofs, "func"))
+       if (!strcasecmp(var, "func"))
                return DIFF_FUNCINFO;
        return -1;
 }
@@ -231,6 +232,8 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
 
 int git_diff_basic_config(const char *var, const char *value, void *cb)
 {
+       const char *name;
+
        if (!strcmp(var, "diff.renamelimit")) {
                diff_rename_limit_default = git_config_int(var, value);
                return 0;
@@ -239,14 +242,14 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
        if (userdiff_config(var, value) < 0)
                return -1;
 
-       if (starts_with(var, "diff.color.") || starts_with(var, "color.diff.")) {
-               int slot = parse_diff_color_slot(var, 11);
+       if (skip_prefix(var, "diff.color.", &name) ||
+           skip_prefix(var, "color.diff.", &name)) {
+               int slot = parse_diff_color_slot(name);
                if (slot < 0)
                        return 0;
                if (!value)
                        return config_error_nonbool(var);
-               color_parse(value, var, diff_colors[slot]);
-               return 0;
+               return color_parse(value, diff_colors[slot]);
        }
 
        /* like GNU diff's --suppress-blank-empty option  */
@@ -306,11 +309,26 @@ static const char *external_diff(void)
        return external_diff_cmd;
 }
 
+/*
+ * Keep track of files used for diffing. Sometimes such an entry
+ * refers to a temporary file, sometimes to an existing file, and
+ * sometimes to "/dev/null".
+ */
 static struct diff_tempfile {
-       const char *name; /* filename external diff should read from */
-       char hex[41];
+       /*
+        * filename external diff should read from, or NULL if this
+        * entry is currently not in use:
+        */
+       const char *name;
+
+       char hex[GIT_SHA1_HEXSZ + 1];
        char mode[10];
-       char tmp_path[PATH_MAX];
+
+       /*
+        * If this diff_tempfile instance refers to a temporary file,
+        * this tempfile object is used to manage its lifetime.
+        */
+       struct tempfile tempfile;
 } diff_temp[2];
 
 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
@@ -373,7 +391,7 @@ static unsigned long diff_filespec_size(struct diff_filespec *one)
 {
        if (!DIFF_FILE_VALID(one))
                return 0;
-       diff_populate_filespec(one, 1);
+       diff_populate_filespec(one, CHECK_SIZE_ONLY);
        return one->size;
 }
 
@@ -476,30 +494,63 @@ static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line
        return ws_blank_line(line, len, ecbdata->ws_rule);
 }
 
-static void emit_add_line(const char *reset,
-                         struct emit_callback *ecbdata,
-                         const char *line, int len)
+static void emit_line_checked(const char *reset,
+                             struct emit_callback *ecbdata,
+                             const char *line, int len,
+                             enum color_diff color,
+                             unsigned ws_error_highlight,
+                             char sign)
 {
-       const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
-       const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
+       const char *set = diff_get_color(ecbdata->color_diff, color);
+       const char *ws = NULL;
 
-       if (!*ws)
-               emit_line_0(ecbdata->opt, set, reset, '+', line, len);
-       else if (new_blank_line_at_eof(ecbdata, line, len))
+       if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
+               ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
+               if (!*ws)
+                       ws = NULL;
+       }
+
+       if (!ws)
+               emit_line_0(ecbdata->opt, set, reset, sign, line, len);
+       else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
                /* Blank line at EOF - paint '+' as well */
-               emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
+               emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
        else {
                /* Emit just the prefix, then the rest. */
-               emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
+               emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
                ws_check_emit(line, len, ecbdata->ws_rule,
                              ecbdata->opt->file, set, reset, ws);
        }
 }
 
+static void emit_add_line(const char *reset,
+                         struct emit_callback *ecbdata,
+                         const char *line, int len)
+{
+       emit_line_checked(reset, ecbdata, line, len,
+                         DIFF_FILE_NEW, WSEH_NEW, '+');
+}
+
+static void emit_del_line(const char *reset,
+                         struct emit_callback *ecbdata,
+                         const char *line, int len)
+{
+       emit_line_checked(reset, ecbdata, line, len,
+                         DIFF_FILE_OLD, WSEH_OLD, '-');
+}
+
+static void emit_context_line(const char *reset,
+                             struct emit_callback *ecbdata,
+                             const char *line, int len)
+{
+       emit_line_checked(reset, ecbdata, line, len,
+                         DIFF_CONTEXT, WSEH_CONTEXT, ' ');
+}
+
 static void emit_hunk_header(struct emit_callback *ecbdata,
                             const char *line, int len)
 {
-       const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
+       const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
@@ -516,15 +567,15 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
        if (len < 10 ||
            memcmp(line, atat, 2) ||
            !(ep = memmem(line + 2, len - 2, atat, 2))) {
-               emit_line(ecbdata->opt, plain, reset, line, len);
+               emit_line(ecbdata->opt, context, reset, line, len);
                return;
        }
        ep += 2; /* skip over @@ */
 
        /* The hunk header in fraginfo color */
-       strbuf_add(&msgbuf, frag, strlen(frag));
+       strbuf_addstr(&msgbuf, frag);
        strbuf_add(&msgbuf, line, ep - line);
-       strbuf_add(&msgbuf, reset, strlen(reset));
+       strbuf_addstr(&msgbuf, reset);
 
        /*
         * trailing "\r\n"
@@ -538,15 +589,15 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
                if (*ep != ' ' && *ep != '\t')
                        break;
        if (ep != cp) {
-               strbuf_add(&msgbuf, plain, strlen(plain));
+               strbuf_addstr(&msgbuf, context);
                strbuf_add(&msgbuf, cp, ep - cp);
-               strbuf_add(&msgbuf, reset, strlen(reset));
+               strbuf_addstr(&msgbuf, reset);
        }
 
        if (ep < line + len) {
-               strbuf_add(&msgbuf, func, strlen(func));
+               strbuf_addstr(&msgbuf, func);
                strbuf_add(&msgbuf, ep, line + len - ep);
-               strbuf_add(&msgbuf, reset, strlen(reset));
+               strbuf_addstr(&msgbuf, reset);
        }
 
        strbuf_add(&msgbuf, line + len, org_len - len);
@@ -562,25 +613,16 @@ static struct diff_tempfile *claim_diff_tempfile(void) {
        die("BUG: diff is failing to clean up its tempfiles");
 }
 
-static int remove_tempfile_installed;
-
 static void remove_tempfile(void)
 {
        int i;
        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
-               if (diff_temp[i].name == diff_temp[i].tmp_path)
-                       unlink_or_warn(diff_temp[i].name);
+               if (is_tempfile_active(&diff_temp[i].tempfile))
+                       delete_tempfile(&diff_temp[i].tempfile);
                diff_temp[i].name = NULL;
        }
 }
 
-static void remove_tempfile_on_signal(int signo)
-{
-       remove_tempfile();
-       sigchain_pop(signo);
-       raise(signo);
-}
-
 static void print_line_count(FILE *file, int count)
 {
        switch (count) {
@@ -601,7 +643,6 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
 {
        const char *endp = NULL;
        static const char *nneof = " No newline at end of file\n";
-       const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 
        while (0 < size) {
@@ -611,8 +652,7 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
                len = endp ? (endp - data + 1) : size;
                if (prefix != '+') {
                        ecb->lno_in_preimage++;
-                       emit_line_0(ecb->opt, old, reset, '-',
-                                   data, len);
+                       emit_del_line(reset, ecb, data, len);
                } else {
                        ecb->lno_in_postimage++;
                        emit_add_line(reset, ecb, data, len);
@@ -621,10 +661,10 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
                data += len;
        }
        if (!endp) {
-               const char *plain = diff_get_color(ecb->color_diff,
-                                                  DIFF_PLAIN);
+               const char *context = diff_get_color(ecb->color_diff,
+                                                    DIFF_CONTEXT);
                putc('\n', ecb->opt->file);
-               emit_line_0(ecb->opt, plain, reset, '\\',
+               emit_line_0(ecb->opt, context, reset, '\\',
                            nneof, strlen(nneof));
        }
 }
@@ -1000,8 +1040,9 @@ static void diff_words_show(struct diff_words_data *diff_words)
        xpp.flags = 0;
        /* as only the hunk header will be parsed, we need a 0-context */
        xecfg.ctxlen = 0;
-       xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
-                     &xpp, &xecfg);
+       if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
+                         &xpp, &xecfg))
+               die("unable to generate word diff");
        free(minus.ptr);
        free(plus.ptr);
        if (diff_words->current_plus != diff_words->plus.text.ptr +
@@ -1084,7 +1125,7 @@ static void init_diff_words_data(struct emit_callback *ecbdata,
                struct diff_words_style *st = ecbdata->diff_words->style;
                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
-               st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
+               st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
        }
 }
 
@@ -1160,7 +1201,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 {
        struct emit_callback *ecbdata = priv;
        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
-       const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
+       const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
        struct diff_options *o = ecbdata->opt;
        const char *line_prefix = diff_line_prefix(o);
@@ -1231,7 +1272,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                }
                diff_words_flush(ecbdata);
                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
-                       emit_line(ecbdata->opt, plain, reset, line, len);
+                       emit_line(ecbdata->opt, context, reset, line, len);
                        fputs("~\n", ecbdata->opt->file);
                } else {
                        /*
@@ -1243,22 +1284,32 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                              line++;
                              len--;
                        }
-                       emit_line(ecbdata->opt, plain, reset, line, len);
+                       emit_line(ecbdata->opt, context, reset, line, len);
                }
                return;
        }
 
-       if (line[0] != '+') {
-               const char *color =
-                       diff_get_color(ecbdata->color_diff,
-                                      line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
-               ecbdata->lno_in_preimage++;
-               if (line[0] == ' ')
-                       ecbdata->lno_in_postimage++;
-               emit_line(ecbdata->opt, color, reset, line, len);
-       } else {
+       switch (line[0]) {
+       case '+':
                ecbdata->lno_in_postimage++;
                emit_add_line(reset, ecbdata, line + 1, len - 1);
+               break;
+       case '-':
+               ecbdata->lno_in_preimage++;
+               emit_del_line(reset, ecbdata, line + 1, len - 1);
+               break;
+       case ' ':
+               ecbdata->lno_in_postimage++;
+               ecbdata->lno_in_preimage++;
+               emit_context_line(reset, ecbdata, line + 1, len - 1);
+               break;
+       default:
+               /* incomplete line at the end */
+               ecbdata->lno_in_preimage++;
+               emit_line(ecbdata->opt,
+                         diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
+                         reset, line, len);
+               break;
        }
 }
 
@@ -1907,11 +1958,11 @@ static void show_dirstat(struct diff_options *options)
                        diff_free_filespec_data(p->one);
                        diff_free_filespec_data(p->two);
                } else if (DIFF_FILE_VALID(p->one)) {
-                       diff_populate_filespec(p->one, 1);
+                       diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
                        copied = added = 0;
                        diff_free_filespec_data(p->one);
                } else if (DIFF_FILE_VALID(p->two)) {
-                       diff_populate_filespec(p->two, 1);
+                       diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
                        copied = 0;
                        added = p->two->size;
                        diff_free_filespec_data(p->two);
@@ -2091,7 +2142,6 @@ static unsigned char *deflate_it(char *data,
        unsigned char *deflated;
        git_zstream stream;
 
-       memset(&stream, 0, sizeof(stream));
        git_deflate_init(&stream, zlib_compression_level);
        bound = git_deflate_bound(&stream, size);
        deflated = xmalloc(bound);
@@ -2185,8 +2235,8 @@ int diff_filespec_is_binary(struct diff_filespec *one)
                        one->is_binary = one->driver->binary;
                else {
                        if (!one->data && DIFF_FILE_VALID(one))
-                               diff_populate_filespec(one, 0);
-                       if (one->data)
+                               diff_populate_filespec(one, CHECK_BINARY);
+                       if (one->is_binary == -1 && one->data)
                                one->is_binary = buffer_is_binary(one->data,
                                                one->size);
                        if (one->is_binary == -1)
@@ -2321,6 +2371,19 @@ static void builtin_diff(const char *name_a,
        } else if (!DIFF_OPT_TST(o, TEXT) &&
            ( (!textconv_one && diff_filespec_is_binary(one)) ||
              (!textconv_two && diff_filespec_is_binary(two)) )) {
+               if (!one->data && !two->data &&
+                   S_ISREG(one->mode) && S_ISREG(two->mode) &&
+                   !DIFF_OPT_TST(o, BINARY)) {
+                       if (!hashcmp(one->sha1, two->sha1)) {
+                               if (must_show_header)
+                                       fprintf(o->file, "%s", header.buf);
+                               goto free_ab_and_return;
+                       }
+                       fprintf(o->file, "%s", header.buf);
+                       fprintf(o->file, "%sBinary files %s and %s differ\n",
+                               line_prefix, lbl[0], lbl[1]);
+                       goto free_ab_and_return;
+               }
                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
                        die("unable to read files to diff");
                /* Quite common confusing case */
@@ -2341,6 +2404,7 @@ static void builtin_diff(const char *name_a,
        } else {
                /* Crazy xdl interfaces.. */
                const char *diffopts = getenv("GIT_DIFF_OPTS");
+               const char *v;
                xpparam_t xpp;
                xdemitconf_t xecfg;
                struct emit_callback ecbdata;
@@ -2379,14 +2443,15 @@ static void builtin_diff(const char *name_a,
                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
                if (!diffopts)
                        ;
-               else if (starts_with(diffopts, "--unified="))
-                       xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
-               else if (starts_with(diffopts, "-u"))
-                       xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
+               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);
-               xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
-                             &xpp, &xecfg);
+               if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
+                                 &xpp, &xecfg))
+                       die("unable to generate diff for %s", one->path);
                if (o->word_diff)
                        free_diff_words_data(&ecbdata);
                if (textconv_one)
@@ -2463,8 +2528,9 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
                xpp.flags = o->xdl_opts;
                xecfg.ctxlen = o->context;
                xecfg.interhunkctxlen = o->interhunkcontext;
-               xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
-                             &xpp, &xecfg);
+               if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
+                                 &xpp, &xecfg))
+                       die("unable to generate diffstat for %s", one->path);
        }
 
        diff_free_filespec_data(one);
@@ -2510,8 +2576,9 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
                memset(&xecfg, 0, sizeof(xecfg));
                xecfg.ctxlen = 1; /* at least one context line */
                xpp.flags = 0;
-               xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
-                             &xpp, &xecfg);
+               if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
+                                 &xpp, &xecfg))
+                       die("unable to generate checkdiff for %s", one->path);
 
                if (data.ws_rule & WS_BLANK_AT_EOF) {
                        struct emit_callback ecbdata;
@@ -2540,12 +2607,9 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
 
 struct diff_filespec *alloc_filespec(const char *path)
 {
-       int namelen = strlen(path);
-       struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
+       struct diff_filespec *spec;
 
-       memset(spec, 0, sizeof(*spec));
-       spec->path = (char *)(spec + 1);
-       memcpy(spec->path, path, namelen+1);
+       FLEXPTR_ALLOC_STR(spec, path, path);
        spec->count = 1;
        spec->is_binary = -1;
        return spec;
@@ -2640,21 +2704,21 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
 
 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
 {
-       int len;
-       char *data = xmalloc(100), *dirty = "";
+       struct strbuf buf = STRBUF_INIT;
+       char *dirty = "";
 
        /* Are we looking at the work tree? */
        if (s->dirty_submodule)
                dirty = "-dirty";
 
-       len = snprintf(data, 100,
-                      "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
-       s->data = data;
-       s->size = len;
-       s->should_free = 1;
+       strbuf_addf(&buf, "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
+       s->size = buf.len;
        if (size_only) {
                s->data = NULL;
-               free(data);
+               strbuf_release(&buf);
+       } else {
+               s->data = strbuf_detach(&buf, NULL);
+               s->should_free = 1;
        }
        return 0;
 }
@@ -2664,8 +2728,9 @@ static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
  * grab the data for the blob (or file) for our own in-core comparison.
  * diff_filespec has data and size fields for this purpose.
  */
-int diff_populate_filespec(struct diff_filespec *s, int size_only)
+int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
 {
+       int size_only = flags & CHECK_SIZE_ONLY;
        int err = 0;
        /*
         * demote FAIL to WARN to allow inspecting the situation
@@ -2720,6 +2785,11 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                }
                if (size_only)
                        return 0;
+               if ((flags & CHECK_BINARY) &&
+                   s->size > big_file_threshold && s->is_binary == -1) {
+                       s->is_binary = 1;
+                       return 0;
+               }
                fd = open(s->path, O_RDONLY);
                if (fd < 0)
                        goto err_empty;
@@ -2741,16 +2811,21 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
        }
        else {
                enum object_type type;
-               if (size_only) {
+               if (size_only || (flags & CHECK_BINARY)) {
                        type = sha1_object_info(s->sha1, &s->size);
                        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;
+                       if (size_only)
+                               return 0;
+                       if (s->size > big_file_threshold && s->is_binary == -1) {
+                               s->is_binary = 1;
+                               return 0;
+                       }
                }
+               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;
        }
        return 0;
 }
@@ -2791,8 +2866,7 @@ static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
        strbuf_addstr(&template, "XXXXXX_");
        strbuf_addstr(&template, base);
 
-       fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
-                       strlen(base) + 1);
+       fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
        if (fd < 0)
                die_errno("unable to create temp-file");
        if (convert_to_working_tree(path,
@@ -2802,11 +2876,10 @@ static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
        }
        if (write_in_full(fd, blob, size) != size)
                die_errno("unable to write temp-file");
-       close(fd);
-       temp->name = temp->tmp_path;
-       strcpy(temp->hex, sha1_to_hex(sha1));
-       temp->hex[40] = 0;
-       sprintf(temp->mode, "%06o", mode);
+       close_tempfile(&temp->tempfile);
+       temp->name = get_tempfile_path(&temp->tempfile);
+       sha1_to_hex_r(temp->hex, sha1);
+       xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
        strbuf_release(&buf);
        strbuf_release(&template);
        free(path_dup);
@@ -2823,17 +2896,11 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
                 * a '+' entry produces this for file-1.
                 */
                temp->name = "/dev/null";
-               strcpy(temp->hex, ".");
-               strcpy(temp->mode, ".");
+               xsnprintf(temp->hex, sizeof(temp->hex), ".");
+               xsnprintf(temp->mode, sizeof(temp->mode), ".");
                return temp;
        }
 
-       if (!remove_tempfile_installed) {
-               atexit(remove_tempfile);
-               sigchain_push_common(remove_tempfile_on_signal);
-               remove_tempfile_installed = 1;
-       }
-
        if (!S_ISGITLINK(one->mode) &&
            (!one->sha1_valid ||
             reuse_worktree_file(name, one->sha1, 1))) {
@@ -2858,16 +2925,16 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
                        /* we can borrow from the file in the work tree */
                        temp->name = name;
                        if (!one->sha1_valid)
-                               strcpy(temp->hex, sha1_to_hex(null_sha1));
+                               sha1_to_hex_r(temp->hex, null_sha1);
                        else
-                               strcpy(temp->hex, sha1_to_hex(one->sha1));
+                               sha1_to_hex_r(temp->hex, one->sha1);
                        /* Even though we may sometimes borrow the
                         * contents from the work tree, we always want
                         * one->mode.  mode is trustworthy even when
                         * !(one->sha1_valid), as long as
                         * DIFF_FILE_VALID(one).
                         */
-                       sprintf(temp->mode, "%06o", one->mode);
+                       xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
                }
                return temp;
        }
@@ -2880,6 +2947,16 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
        return temp;
 }
 
+static void add_external_diff_name(struct argv_array *argv,
+                                  const char *name,
+                                  struct diff_filespec *df)
+{
+       struct diff_tempfile *temp = prepare_temp_file(name, df);
+       argv_array_push(argv, temp->name);
+       argv_array_push(argv, temp->hex);
+       argv_array_push(argv, temp->mode);
+}
+
 /* An external diff command takes:
  *
  * diff-cmd name infile1 infile1-sha1 infile1-mode \
@@ -2896,48 +2973,32 @@ static void run_external_diff(const char *pgm,
                              struct diff_options *o)
 {
        struct argv_array argv = ARGV_ARRAY_INIT;
-       int retval;
+       struct argv_array env = ARGV_ARRAY_INIT;
        struct diff_queue_struct *q = &diff_queued_diff;
-       const char *env[3] = { NULL };
-       char env_counter[50];
-       char env_total[50];
+
+       argv_array_push(&argv, pgm);
+       argv_array_push(&argv, name);
 
        if (one && two) {
-               struct diff_tempfile *temp_one, *temp_two;
-               const char *othername = (other ? other : name);
-               temp_one = prepare_temp_file(name, one);
-               temp_two = prepare_temp_file(othername, two);
-               argv_array_push(&argv, pgm);
-               argv_array_push(&argv, name);
-               argv_array_push(&argv, temp_one->name);
-               argv_array_push(&argv, temp_one->hex);
-               argv_array_push(&argv, temp_one->mode);
-               argv_array_push(&argv, temp_two->name);
-               argv_array_push(&argv, temp_two->hex);
-               argv_array_push(&argv, temp_two->mode);
-               if (other) {
+               add_external_diff_name(&argv, name, one);
+               if (!other)
+                       add_external_diff_name(&argv, name, two);
+               else {
+                       add_external_diff_name(&argv, other, two);
                        argv_array_push(&argv, other);
                        argv_array_push(&argv, xfrm_msg);
                }
-       } else {
-               argv_array_push(&argv, pgm);
-               argv_array_push(&argv, name);
        }
-       fflush(NULL);
 
-       env[0] = env_counter;
-       snprintf(env_counter, sizeof(env_counter), "GIT_DIFF_PATH_COUNTER=%d",
-                ++o->diff_path_counter);
-       env[1] = env_total;
-       snprintf(env_total, sizeof(env_total), "GIT_DIFF_PATH_TOTAL=%d", q->nr);
+       argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
+       argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
+
+       if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
+               die(_("external diff died, stopping at %s"), name);
 
-       retval = run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env);
        remove_tempfile();
        argv_array_clear(&argv);
-       if (retval) {
-               fprintf(stderr, "external diff died, stopping at %s.\n", name);
-               exit(1);
-       }
+       argv_array_clear(&env);
 }
 
 static int similarity_index(struct diff_filepair *p)
@@ -3203,8 +3264,10 @@ void diff_setup(struct diff_options *options)
        options->rename_limit = -1;
        options->dirstat_permille = diff_dirstat_permille_default;
        options->context = diff_context_default;
+       options->ws_error_highlight = WSEH_NEW;
        DIFF_OPT_SET(options, RENAME_EMPTY);
 
+       /* pathchange left =NULL by default */
        options->change = diff_change;
        options->add_remove = diff_addremove;
        options->use_color = diff_use_color_default;
@@ -3396,12 +3459,10 @@ int parse_long_opt(const char *opt, const char **argv,
                   const char **optarg)
 {
        const char *arg = argv[0];
-       if (arg[0] != '-' || arg[1] != '-')
+       if (!skip_prefix(arg, "--", &arg))
                return 0;
-       arg += strlen("--");
-       if (!starts_with(arg, opt))
+       if (!skip_prefix(arg, opt, &arg))
                return 0;
-       arg += strlen(opt);
        if (*arg == '=') { /* stuck form: --option=value */
                *optarg = arg + 1;
                return 1;
@@ -3425,13 +3486,13 @@ static int stat_opt(struct diff_options *options, const char **av)
        int count = options->stat_count;
        int argcount = 1;
 
-       arg += strlen("--stat");
+       if (!skip_prefix(arg, "--stat", &arg))
+               die("BUG: stat option does not begin with --stat: %s", arg);
        end = (char *)arg;
 
        switch (*arg) {
        case '-':
-               if (starts_with(arg, "-width")) {
-                       arg += strlen("-width");
+               if (skip_prefix(arg, "-width", &arg)) {
                        if (*arg == '=')
                                width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
@@ -3440,8 +3501,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                                width = strtoul(av[1], &end, 10);
                                argcount = 2;
                        }
-               } else if (starts_with(arg, "-name-width")) {
-                       arg += strlen("-name-width");
+               } else if (skip_prefix(arg, "-name-width", &arg)) {
                        if (*arg == '=')
                                name_width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
@@ -3450,8 +3510,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                                name_width = strtoul(av[1], &end, 10);
                                argcount = 2;
                        }
-               } else if (starts_with(arg, "-graph-width")) {
-                       arg += strlen("-graph-width");
+               } else if (skip_prefix(arg, "-graph-width", &arg)) {
                        if (*arg == '=')
                                graph_width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
@@ -3460,8 +3519,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                                graph_width = strtoul(av[1], &end, 10);
                                argcount = 2;
                        }
-               } else if (starts_with(arg, "-count")) {
-                       arg += strlen("-count");
+               } else if (skip_prefix(arg, "-count", &arg)) {
                        if (*arg == '=')
                                count = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
@@ -3593,12 +3651,55 @@ static void enable_patch_output(int *fmt) {
        *fmt |= DIFF_FORMAT_PATCH;
 }
 
-int diff_opt_parse(struct diff_options *options, const char **av, int ac)
+static int parse_one_token(const char **arg, const char *token)
+{
+       const char *rest;
+       if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
+               *arg = rest;
+               return 1;
+       }
+       return 0;
+}
+
+static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
+{
+       const char *orig_arg = arg;
+       unsigned val = 0;
+       while (*arg) {
+               if (parse_one_token(&arg, "none"))
+                       val = 0;
+               else if (parse_one_token(&arg, "default"))
+                       val = WSEH_NEW;
+               else if (parse_one_token(&arg, "all"))
+                       val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
+               else if (parse_one_token(&arg, "new"))
+                       val |= WSEH_NEW;
+               else if (parse_one_token(&arg, "old"))
+                       val |= WSEH_OLD;
+               else if (parse_one_token(&arg, "context"))
+                       val |= WSEH_CONTEXT;
+               else {
+                       error("unknown value after ws-error-highlight=%.*s",
+                             (int)(arg - orig_arg), orig_arg);
+                       return 0;
+               }
+               if (*arg)
+                       arg++;
+       }
+       opt->ws_error_highlight = val;
+       return 1;
+}
+
+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 = "";
+
        /* Output format options */
        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
            || opt_arg(arg, 'U', "unified", &options->context))
@@ -3614,17 +3715,17 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                options->output_format |= DIFF_FORMAT_SHORTSTAT;
        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
                return parse_dirstat_opt(options, "");
-       else if (starts_with(arg, "-X"))
-               return parse_dirstat_opt(options, arg + 2);
-       else if (starts_with(arg, "--dirstat="))
-               return parse_dirstat_opt(options, arg + 10);
+       else if (skip_prefix(arg, "-X", &arg))
+               return parse_dirstat_opt(options, arg);
+       else if (skip_prefix(arg, "--dirstat=", &arg))
+               return parse_dirstat_opt(options, arg);
        else if (!strcmp(arg, "--cumulative"))
                return parse_dirstat_opt(options, "cumulative");
        else if (!strcmp(arg, "--dirstat-by-file"))
                return parse_dirstat_opt(options, "files");
-       else if (starts_with(arg, "--dirstat-by-file=")) {
+       else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
                parse_dirstat_opt(options, "files");
-               return parse_dirstat_opt(options, arg + 18);
+               return parse_dirstat_opt(options, arg);
        }
        else if (!strcmp(arg, "--check"))
                options->output_format |= DIFF_FORMAT_CHECKDIFF;
@@ -3674,9 +3775,9 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                DIFF_OPT_CLR(options, RENAME_EMPTY);
        else if (!strcmp(arg, "--relative"))
                DIFF_OPT_SET(options, RELATIVE_NAME);
-       else if (starts_with(arg, "--relative=")) {
+       else if (skip_prefix(arg, "--relative=", &arg)) {
                DIFF_OPT_SET(options, RELATIVE_NAME);
-               options->prefix = arg + 11;
+               options->prefix = arg;
        }
 
        /* xdiff options */
@@ -3723,12 +3824,13 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
        else if (!strcmp(arg, "--follow"))
                DIFF_OPT_SET(options, FOLLOW_RENAMES);
-       else if (!strcmp(arg, "--no-follow"))
+       else if (!strcmp(arg, "--no-follow")) {
                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
-       else if (!strcmp(arg, "--color"))
+               DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
+       } else if (!strcmp(arg, "--color"))
                options->use_color = 1;
-       else if (starts_with(arg, "--color=")) {
-               int value = git_config_colorbool(NULL, arg+8);
+       else if (skip_prefix(arg, "--color=", &arg)) {
+               int value = git_config_colorbool(NULL, arg);
                if (value < 0)
                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
                options->use_color = value;
@@ -3739,29 +3841,28 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                options->use_color = 1;
                options->word_diff = DIFF_WORDS_COLOR;
        }
-       else if (starts_with(arg, "--color-words=")) {
+       else if (skip_prefix(arg, "--color-words=", &arg)) {
                options->use_color = 1;
                options->word_diff = DIFF_WORDS_COLOR;
-               options->word_regex = arg + 14;
+               options->word_regex = arg;
        }
        else if (!strcmp(arg, "--word-diff")) {
                if (options->word_diff == DIFF_WORDS_NONE)
                        options->word_diff = DIFF_WORDS_PLAIN;
        }
-       else if (starts_with(arg, "--word-diff=")) {
-               const char *type = arg + 12;
-               if (!strcmp(type, "plain"))
+       else if (skip_prefix(arg, "--word-diff=", &arg)) {
+               if (!strcmp(arg, "plain"))
                        options->word_diff = DIFF_WORDS_PLAIN;
-               else if (!strcmp(type, "color")) {
+               else if (!strcmp(arg, "color")) {
                        options->use_color = 1;
                        options->word_diff = DIFF_WORDS_COLOR;
                }
-               else if (!strcmp(type, "porcelain"))
+               else if (!strcmp(arg, "porcelain"))
                        options->word_diff = DIFF_WORDS_PORCELAIN;
-               else if (!strcmp(type, "none"))
+               else if (!strcmp(arg, "none"))
                        options->word_diff = DIFF_WORDS_NONE;
                else
-                       die("bad --word-diff argument: %s", type);
+                       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)
@@ -3784,13 +3885,15 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
        else if (!strcmp(arg, "--ignore-submodules")) {
                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
                handle_ignore_submodules_arg(options, "all");
-       } else if (starts_with(arg, "--ignore-submodules=")) {
+       } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
-               handle_ignore_submodules_arg(options, arg + 20);
+               handle_ignore_submodules_arg(options, arg);
        } else if (!strcmp(arg, "--submodule"))
                DIFF_OPT_SET(options, SUBMODULE_LOG);
-       else if (starts_with(arg, "--submodule="))
-               return parse_submodule_opt(options, arg + 12);
+       else if (skip_prefix(arg, "--submodule=", &arg))
+               return parse_submodule_opt(options, arg);
+       else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
+               return parse_ws_error_highlight(options, arg);
 
        /* misc options */
        else if (!strcmp(arg, "-z"))
@@ -3813,7 +3916,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
        else if (!strcmp(arg, "--pickaxe-regex"))
                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
        else if ((argcount = short_opt('O', av, &optarg))) {
-               options->orderfile = optarg;
+               const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+               options->orderfile = xstrdup(path);
                return argcount;
        }
        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
@@ -3825,8 +3929,8 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
        }
        else if (!strcmp(arg, "--abbrev"))
                options->abbrev = DEFAULT_ABBREV;
-       else if (starts_with(arg, "--abbrev=")) {
-               options->abbrev = strtoul(arg + 9, NULL, 10);
+       else if (skip_prefix(arg, "--abbrev=", &arg)) {
+               options->abbrev = strtoul(arg, NULL, 10);
                if (options->abbrev < MINIMUM_ABBREV)
                        options->abbrev = MINIMUM_ABBREV;
                else if (40 < options->abbrev)
@@ -3852,9 +3956,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
        else if (!strcmp(arg, "--no-function-context"))
                DIFF_OPT_CLR(options, FUNCCONTEXT);
        else if ((argcount = parse_long_opt("output", av, &optarg))) {
-               options->file = fopen(optarg, "w");
+               const char *path = prefix_filename(prefix, strlen(prefix), optarg);
+               options->file = fopen(path, "w");
                if (!options->file)
-                       die_errno("Could not open '%s'", optarg);
+                       die_errno("Could not open '%s'", path);
                options->close_file = 1;
                return argcount;
        } else
@@ -3907,16 +4012,13 @@ static int diff_scoreopt_parse(const char *opt)
        cmd = *opt++;
        if (cmd == '-') {
                /* convert the long-form arguments into short-form versions */
-               if (starts_with(opt, "break-rewrites")) {
-                       opt += strlen("break-rewrites");
+               if (skip_prefix(opt, "break-rewrites", &opt)) {
                        if (*opt == 0 || *opt++ == '=')
                                cmd = 'B';
-               } else if (starts_with(opt, "find-copies")) {
-                       opt += strlen("find-copies");
+               } else if (skip_prefix(opt, "find-copies", &opt)) {
                        if (*opt == 0 || *opt++ == '=')
                                cmd = 'C';
-               } else if (starts_with(opt, "find-renames")) {
-                       opt += strlen("find-renames");
+               } else if (skip_prefix(opt, "find-renames", &opt)) {
                        if (*opt == 0 || *opt++ == '=')
                                cmd = 'M';
                }
@@ -3984,9 +4086,9 @@ const char *diff_unique_abbrev(const unsigned char *sha1, int len)
        if (abblen < 37) {
                static char hex[41];
                if (len < abblen && abblen <= len + 2)
-                       sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
+                       xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
                else
-                       sprintf(hex, "%s...", abbrev);
+                       xsnprintf(hex, sizeof(hex), "%s...", abbrev);
                return hex;
        }
        return sha1_to_hex(sha1);
@@ -4413,8 +4515,10 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
                xpp.flags = 0;
                xecfg.ctxlen = 3;
                xecfg.flags = 0;
-               xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
-                             &xpp, &xecfg);
+               if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
+                                 &xpp, &xecfg))
+                       return error("unable to generate patch-id diff for %s",
+                                    p->one->path);
        }
 
        git_SHA1_Final(sha1, &ctx);
@@ -4528,7 +4632,7 @@ void diff_flush(struct diff_options *options)
                        show_stats(&diffstat, options);
                if (output_format & DIFF_FORMAT_SHORTSTAT)
                        show_shortstats(&diffstat, options);
-               if (output_format & DIFF_FORMAT_DIRSTAT)
+               if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
                        show_dirstat_by_line(&diffstat, options);
                free_diffstat_info(&diffstat);
                separator++;
@@ -4698,8 +4802,8 @@ static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
            !DIFF_FILE_VALID(p->two) ||
            (p->one->sha1_valid && p->two->sha1_valid) ||
            (p->one->mode != p->two->mode) ||
-           diff_populate_filespec(p->one, 1) ||
-           diff_populate_filespec(p->two, 1) ||
+           diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
+           diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
            (p->one->size != p->two->size) ||
            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
                p->skip_stat_unmatch_result = 1;
@@ -4752,6 +4856,7 @@ void diffcore_fix_diff_index(struct diff_options *options)
 
 void diffcore_std(struct diff_options *options)
 {
+       /* NOTE please keep the following in sync with diff_tree_combined() */
        if (options->skip_stat_unmatch)
                diffcore_skip_stat_unmatch(options);
        if (!options->found_follow) {
@@ -4940,7 +5045,7 @@ static char *run_textconv(const char *pgm, struct diff_filespec *spec,
        struct diff_tempfile *temp;
        const char *argv[3];
        const char **arg = argv;
-       struct child_process child;
+       struct child_process child = CHILD_PROCESS_INIT;
        struct strbuf buf = STRBUF_INIT;
        int err = 0;
 
@@ -4949,7 +5054,6 @@ static char *run_textconv(const char *pgm, struct diff_filespec *spec,
        *arg++ = temp->name;
        *arg = NULL;
 
-       memset(&child, 0, sizeof(child));
        child.use_shell = 1;
        child.argv = argv;
        child.out = -1;
@@ -4978,7 +5082,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 {
        size_t size;
 
-       if (!driver || !driver->textconv) {
+       if (!driver) {
                if (!DIFF_FILE_VALID(df)) {
                        *outbuf = "";
                        return 0;
@@ -4989,6 +5093,9 @@ size_t fill_textconv(struct userdiff_driver *driver,
                return df->size;
        }
 
+       if (!driver->textconv)
+               die("BUG: fill_textconv called with non-textconv driver");
+
        if (driver->textconv_cache && df->sha1_valid) {
                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
                                          &size);