[PATCH] show-diff.c: adjust default format for the Linux kernel.

[git.git] / show-diff.c

diff --git a/show-diff.c b/show-diff.c
index a00ee72..32d2fce 100644 (file)
--- a/show-diff.c
+++ b/show-diff.c
@@ -4,9 +4,8 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 #include "cache.h"
-#include <ctype.h>
 
-static char *diff_cmd = "diff -L '%s' -u -N  - '%s'";
+static char *diff_cmd = "diff -L 'a/%s' -L 'b/%s' -p -u - '%s'";
 
 /* Help to copy the thing properly quoted for the shell safety.
  * any single quote is replaced with '\'', and the caller is
@@ -24,21 +23,16 @@ static char *diff_cmd = "diff -L '%s' -u -N  - '%s'";
 static char *sq_expand(char *src)
 {
        static char *buf = NULL;
-       static int buf_size = -1;
        int cnt, c;
        char *cp;
 
-       /* count single quote characters */ 
-       for (cnt = 0, cp = src; *cp; cnt++, cp++)
+       /* count bytes needed to store the quoted string. */ 
+       for (cnt = 1, cp = src; *cp; cnt++, cp++)
                if (*cp == '\'')
                        cnt += 3;
 
-       if (buf_size < cnt) {
-               free(buf);
-               buf_size = cnt;
-               buf = malloc(cnt);
-       }
-
+       if (! (buf = malloc(cnt)))
+           return buf;
        cp = buf;
        while ((c = *src++)) {
                if (c != '\'')
@@ -52,66 +46,44 @@ static char *sq_expand(char *src)
        return buf;
 }
 
-static void show_differences(char *name, void *old_contents,
+static void show_differences(char *name, char *label, void *old_contents,
                             unsigned long long old_size)
 {
        FILE *f;
-       static char *cmd = NULL;
-       static int cmd_size = -1;
-
        char *name_sq = sq_expand(name);
-       int cmd_required_length = strlen(name_sq) * 2 + strlen(diff_cmd);
+       char *label_sq = (name != label) ? sq_expand(label) : name_sq;
+       int cmd_size = strlen(name_sq) +
+               strlen(label_sq) * 2 + strlen(diff_cmd);
+       char *cmd = malloc(cmd_size);
 
-       if (cmd_size < cmd_required_length) {
-               free(cmd);
-               cmd_size = cmd_required_length;
-               cmd = malloc(cmd_required_length);
-       }
-       snprintf(cmd, cmd_size, diff_cmd, name_sq, name_sq);
+       fflush(stdout);
+       snprintf(cmd, cmd_size, diff_cmd, label_sq, label_sq, name_sq);
        f = popen(cmd, "w");
        if (old_size)
                fwrite(old_contents, old_size, 1, f);
        pclose(f);
+       if (label_sq != name_sq)
+               free(label_sq);
+       free(name_sq);
+       free(cmd);
 }
 
 static void show_diff_empty(struct cache_entry *ce)
 {
        char *old;
        unsigned long int size;
-       int lines=0;
-       unsigned char type[20], *p, *end;
+       unsigned char type[20];
 
        old = read_sha1_file(ce->sha1, type, &size);
-       if (size > 0) {
-               int startline = 1;
-               int c = 0;
-
-               printf("--- %s\n", ce->name);
-               printf("+++ /dev/null\n");
-               p = old;
-               end = old + size;
-               while (p < end)
-                       if (*p++ == '\n')
-                               lines ++;
-               printf("@@ -1,%d +0,0 @@\n", lines);
-               p = old;
-               while (p < end) {
-                       c = *p++;
-                       if (startline) {
-                               putchar('-');
-                               startline = 0;
-                       }
-                       putchar(c);
-                       if (c == '\n')
-                               startline = 1;
-               }
-               if (c!='\n')
-                       printf("\n");
-               fflush(stdout);
+       if (! old) {
+               error("unable to read blob object for %s (%s)", ce->name,
+                     sha1_to_hex(ce->sha1));
+               return;
        }
+       show_differences("/dev/null", ce->name, old, size);
 }
 
-static const char *show_diff_usage = "show-diff [-s] [-q] [-z] [paths...]";
+static const char *show_diff_usage = "show-diff [-q] [-s] [-z] [paths...]";
 
 static int matches_pathspec(struct cache_entry *ce, char **spec, int cnt)
 {
@@ -141,9 +113,8 @@ int main(int argc, char **argv)
                        silent_on_nonexisting_files = silent = 1;
                else if (!strcmp(argv[1], "-q"))
                        silent_on_nonexisting_files = 1;
-               else if (!strcmp(argv[1], "-z")) {
+               else if (!strcmp(argv[1], "-z"))
                        machine_readable = 1;
-               }
                else
                        usage(show_diff_usage);
                argv++; argc--;
@@ -164,10 +135,23 @@ int main(int argc, char **argv)
                char type[20];
                void *old;
 
-               if (1 <argc &&
+               if (1 < argc &&
                    ! matches_pathspec(ce, argv+1, argc-1))
                        continue;
 
+               if (ce_stage(ce)) {
+                       if (machine_readable)
+                               printf("U %s%c", ce->name, 0);
+                       else
+                               printf("%s: Unmerged\n",
+                                      ce->name);
+                       while (i < entries &&
+                              !strcmp(ce->name, active_cache[i]->name))
+                               i++;
+                       i--; /* compensate for loop control increments */
+                       continue;
+               }
+ 
                if (stat(ce->name, &st) < 0) {
                        if (errno == ENOENT && silent_on_nonexisting_files)
                                continue;
@@ -189,12 +173,15 @@ int main(int argc, char **argv)
                        printf("%s %s%c", sha1_to_hex(ce->sha1), ce->name, 0);
                        continue;
                }
-               fflush(stdout);
                if (silent)
                        continue;
 
                old = read_sha1_file(ce->sha1, type, &size);
-               show_differences(ce->name, old, size);
+               if (! old)
+                       error("unable to read blob object for %s (%s)",
+                             ce->name, sha1_to_hex(ce->sha1));
+               else
+                       show_differences(ce->name, ce->name, old, size);
                free(old);
        }
        return 0;