Merge branch 'maint'

* maint:
  tutorial: gentler illustration of Alice/Bob workflow using gitk
  pretty=format: respect date format options
  make git-shell paranoid about closed stdin/stdout/stderr
  Document gitk --argscmd flag.
  Fix '--dirstat' with cross-directory renaming
  for-each-ref: Allow a trailing slash in the patterns

diff --combined commit.h
index d163c7487b0dd65d6c0cc9cb568c3ae44e30726d,ecdd5733f989f5931a0af05b387321da7068e9f9..de15f4d715ded4d8fd4f882b44fd9a320e7cdb2e
--- 1/commit.h
--- 2/commit.h
+++ b/commit.h
@@@ -67,7 -67,8 +67,8 @@@ extern int non_ascii(int)
  struct rev_info; /* in revision.h, it circularly uses enum cmit_fmt */
  extern void get_commit_format(const char *arg, struct rev_info *);
  extern void format_commit_message(const struct commit *commit,
-                                   const void *format, struct strbuf *sb);
+                                 const void *format, struct strbuf *sb,
+                                 enum date_mode dmode);
  extern void pretty_print_commit(enum cmit_fmt fmt, const struct commit*,
                                  struct strbuf *,
                                  int abbrev, const char *subject,
@@@ -121,7 -122,6 +122,7 @@@ int read_graft_file(const char *graft_f
  struct commit_graft *lookup_commit_graft(const unsigned char *sha1);
  
  extern struct commit_list *get_merge_bases(struct commit *rev1, struct commit *rev2, int cleanup);
 +extern struct commit_list *get_merge_bases_many(struct commit *one, int n, struct commit **twos, int cleanup);
  extern struct commit_list *get_octopus_merge_bases(struct commit_list *in);
  
  extern int register_shallow(const unsigned char *sha1);

diff --combined diff.c
index 18fa7a712cc3a40ae8ce30295e5daf72bf015c95,7b4300a74ab116bdf96ef015322a7533204fd18f..135dec459a0f5d0abba812d773d7962d460e078f
--- 1/diff.c
--- 2/diff.c
+++ b/diff.c
@@@ -20,7 -20,6 +20,7 @@@
  
  static int diff_detect_rename_default;
  static int diff_rename_limit_default = 200;
 +static int diff_suppress_blank_empty;
  int diff_use_color_default = -1;
  static const char *external_diff_cmd_cfg;
  int diff_auto_refresh_index = 1;
@@@ -177,12 -176,6 +177,12 @@@ int git_diff_basic_config(const char *v
                return 0;
        }
  
 +      /* like GNU diff's --suppress-blank-empty option  */
 +      if (!strcmp(var, "diff.suppress-blank-empty")) {
 +              diff_suppress_blank_empty = git_config_bool(var, value);
 +              return 0;
 +      }
 +
        if (!prefixcmp(var, "diff.")) {
                const char *ep = strrchr(var, '.');
                if (ep != var + 4) {
@@@ -376,6 -369,7 +376,6 @@@ static void diff_words_append(char *lin
  }
  
  struct diff_words_data {
 -      struct xdiff_emit_state xm;
        struct diff_words_buffer minus, plus;
        FILE *file;
  };
@@@ -465,8 -459,11 +465,8 @@@ static void diff_words_show(struct diff
  
        xpp.flags = XDF_NEED_MINIMAL;
        xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 -      ecb.outf = xdiff_outf;
 -      ecb.priv = diff_words;
 -      diff_words->xm.consume = fn_out_diff_words_aux;
 -      xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 -
 +      xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 +                    &xpp, &xecfg, &ecb);
        free(minus.ptr);
        free(plus.ptr);
        diff_words->minus.text.size = diff_words->plus.text.size = 0;
@@@ -480,6 -477,7 +480,6 @@@
  typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
  
  struct emit_callback {
 -      struct xdiff_emit_state xm;
        int nparents, color_diff;
        unsigned ws_rule;
        sane_truncate_fn truncate;
@@@ -582,12 -580,6 +582,12 @@@ static void fn_out_consume(void *priv, 
                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
        }
  
 +      if (diff_suppress_blank_empty
 +          && len == 2 && line[0] == ' ' && line[1] == '\n') {
 +              line[0] = '\n';
 +              len = 1;
 +      }
 +
        /* This is not really necessary for now because
         * this codepath only deals with two-way diffs.
         */
@@@ -716,6 -708,8 +716,6 @@@ static char *pprint_rename(const char *
  }
  
  struct diffstat_t {
 -      struct xdiff_emit_state xm;
 -
        int nr;
        int alloc;
        struct diffstat_file {
@@@ -1060,6 -1054,13 +1060,13 @@@ static long gather_dirstat(FILE *file, 
        return this_dir;
  }
  
+ static int dirstat_compare(const void *_a, const void *_b)
+ {
+       const struct dirstat_file *a = _a;
+       const struct dirstat_file *b = _b;
+       return strcmp(a->name, b->name);
+ }
+ 
  static void show_dirstat(struct diff_options *options)
  {
        int i;
@@@ -1119,6 -1120,7 +1126,7 @@@
                return;
  
        /* Show all directories with more than x% of the changes */
+       qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
        gather_dirstat(options->file, &dir, changed, "", 0);
  }
  
@@@ -1137,6 -1139,7 +1145,6 @@@ static void free_diffstat_info(struct d
  }
  
  struct checkdiff_t {
 -      struct xdiff_emit_state xm;
        const char *filename;
        int lineno;
        struct diff_options *o;
@@@ -1381,8 -1384,6 +1389,8 @@@ static struct builtin_funcname_pattern 
        const char *name;
        const char *pattern;
  } builtin_funcname_pattern[] = {
 +      { "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
 +      { "html", "^\\s*\\(<[Hh][1-6]\\s.*>.*\\)$" },
        { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
                        "new\\|return\\|switch\\|throw\\|while\\)\n"
                        "^[     ]*\\(\\([       ]*"
@@@ -1394,9 -1395,9 +1402,9 @@@
                        "\\|"
                        "^\\(.*=[ \t]*\\(class\\|record\\).*\\)$"
                        },
 -      { "bibtex", "\\(@[a-zA-Z]\\{1,\\}[ \t]*{\\{0,1\\}[ \t]*[^ \t\"@',\\#}{~%]*\\).*$" },
 -      { "tex", "^\\(\\\\\\(\\(sub\\)*section\\|chapter\\|part\\)\\*\\{0,1\\}{.*\\)$" },
 +      { "python", "^\\s*\\(\\(class\\|def\\)\\s.*\\)$" },
        { "ruby", "^\\s*\\(\\(class\\|module\\|def\\)\\s.*\\)$" },
 +      { "tex", "^\\(\\\\\\(\\(sub\\)*section\\|chapter\\|part\\)\\*\\{0,1\\}{.*\\)$" },
  };
  
  static const char *diff_funcname_pattern(struct diff_filespec *one)
@@@ -1528,13 -1529,15 +1536,13 @@@ static void builtin_diff(const char *na
                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
                else if (!prefixcmp(diffopts, "-u"))
                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 -              ecb.outf = xdiff_outf;
 -              ecb.priv = &ecbdata;
 -              ecbdata.xm.consume = fn_out_consume;
                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
                        ecbdata.diff_words =
                                xcalloc(1, sizeof(struct diff_words_data));
                        ecbdata.diff_words->file = o->file;
                }
 -              xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 +              xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
 +                            &xpp, &xecfg, &ecb);
                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
                        free_diff_words_data(&ecbdata);
        }
@@@ -1585,8 -1588,9 +1593,8 @@@ static void builtin_diffstat(const cha
  
                memset(&xecfg, 0, sizeof(xecfg));
                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
 -              ecb.outf = xdiff_outf;
 -              ecb.priv = diffstat;
 -              xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 +              xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
 +                            &xpp, &xecfg, &ecb);
        }
  
   free_and_return:
@@@ -1607,6 -1611,7 +1615,6 @@@ static void builtin_checkdiff(const cha
                return;
  
        memset(&data, 0, sizeof(data));
 -      data.xm.consume = checkdiff_consume;
        data.filename = name_b ? name_b : name_a;
        data.lineno = 0;
        data.o = o;
@@@ -1632,8 -1637,9 +1640,8 @@@
                memset(&xecfg, 0, sizeof(xecfg));
                xecfg.ctxlen = 1; /* at least one context line */
                xpp.flags = XDF_NEED_MINIMAL;
 -              ecb.outf = xdiff_outf;
 -              ecb.priv = &data;
 -              xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 +              xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
 +                            &xpp, &xecfg, &ecb);
  
                if ((data.ws_rule & WS_TRAILING_SPACE) &&
                    data.trailing_blanks_start) {
@@@ -3021,6 -3027,7 +3029,6 @@@ static void diff_summary(FILE *file, st
  }
  
  struct patch_id_t {
 -      struct xdiff_emit_state xm;
        SHA_CTX *ctx;
        int patchlen;
  };
@@@ -3065,6 -3072,7 +3073,6 @@@ static int diff_get_patch_id(struct dif
        SHA1_Init(&ctx);
        memset(&data, 0, sizeof(struct patch_id_t));
        data.ctx = &ctx;
 -      data.xm.consume = patch_id_consume;
  
        for (i = 0; i < q->nr; i++) {
                xpparam_t xpp;
@@@ -3129,8 -3137,9 +3137,8 @@@
                xpp.flags = XDF_NEED_MINIMAL;
                xecfg.ctxlen = 3;
                xecfg.flags = XDL_EMIT_FUNCNAMES;
 -              ecb.outf = xdiff_outf;
 -              ecb.priv = &data;
 -              xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 +              xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
 +                            &xpp, &xecfg, &ecb);
        }
  
        SHA1_Final(sha1, &ctx);
@@@ -3207,6 -3216,7 +3215,6 @@@ void diff_flush(struct diff_options *op
                struct diffstat_t diffstat;
  
                memset(&diffstat, 0, sizeof(struct diffstat_t));
 -              diffstat.xm.consume = diffstat_consume;
                for (i = 0; i < q->nr; i++) {
                        struct diff_filepair *p = q->queue[i];
                        if (check_pair_status(p))

diff --combined shell.c
index 0f6a727a8c267cdeb3a93c30bc688bb64ecd8003,ad60200d28e9957f54a34435f5dc59fce412666c..e3393690dd3b79af80e6b95710583e744fd574d4
--- 1/shell.c
--- 2/shell.c
+++ b/shell.c
@@@ -3,6 -3,14 +3,6 @@@
  #include "exec_cmd.h"
  #include "strbuf.h"
  
 -/* Stubs for functions that make no sense for git-shell. These stubs
 - * are provided here to avoid linking in external redundant modules.
 - */
 -void release_pack_memory(size_t need, int fd){}
 -void trace_argv_printf(const char **argv, const char *fmt, ...){}
 -void trace_printf(const char *fmt, ...){}
 -
 -
  static int do_generic_cmd(const char *me, char *arg)
  {
        const char *my_argv[4];
@@@ -48,6 -56,19 +48,19 @@@ int main(int argc, char **argv
  {
        char *prog;
        struct commands *cmd;
+       int devnull_fd;
+ 
+       /*
+        * Always open file descriptors 0/1/2 to avoid clobbering files
+        * in die().  It also avoids not messing up when the pipes are
+        * dup'ed onto stdin/stdout/stderr in the child processes we spawn.
+        */
+       devnull_fd = open("/dev/null", O_RDWR);
+       while (devnull_fd >= 0 && devnull_fd <= 2)
+               devnull_fd = dup(devnull_fd);
+       if (devnull_fd == -1)
+               die("opening /dev/null failed (%s)", strerror(errno));
+       close (devnull_fd);
  
        /*
         * Special hack to pretend to be a CVS server