revision.c: explain what tree_difference does

diff --git a/diff.c b/diff.c
index 81be6adca3541cd8785e80f6a8f6db61ad11b272..d8f9242ea8fe2ee92884623939a85b6587a3ad9d 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -1364,6 +1364,32 @@ static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
        return e;
 }
 
+static int populate_from_stdin(struct diff_filespec *s)
+{
+#define INCREMENT 1024
+       char *buf;
+       unsigned long size;
+       int got;
+
+       size = 0;
+       buf = NULL;
+       while (1) {
+               buf = xrealloc(buf, size + INCREMENT);
+               got = xread(0, buf + size, INCREMENT);
+               if (!got)
+                       break; /* EOF */
+               if (got < 0)
+                       return error("error while reading from stdin %s",
+                                    strerror(errno));
+               size += got;
+       }
+       s->should_munmap = 0;
+       s->data = buf;
+       s->size = size;
+       s->should_free = 1;
+       return 0;
+}
+
 /*
  * While doing rename detection and pickaxe operation, we may need to
  * grab the data for the blob (or file) for our own in-core comparison.
@@ -1389,22 +1415,9 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                char *buf;
                unsigned long size;
 
-               if (!strcmp(s->path, "-")) {
-#define INCREMENT 1024
-                       int i = INCREMENT;
-                       size = 0;
-                       buf = NULL;
-                       while (i == INCREMENT) {
-                               buf = xrealloc(buf, size + INCREMENT);
-                               i = xread(0, buf + size, INCREMENT);
-                               size += i;
-                       }
-                       s->should_munmap = 0;
-                       s->data = buf;
-                       s->size = size;
-                       s->should_free = 1;
-                       return 0;
-               }
+               if (!strcmp(s->path, "-"))
+                       return populate_from_stdin(s);
+
                if (lstat(s->path, &st) < 0) {
                        if (errno == ENOENT) {
                        err_empty:
@@ -1415,7 +1428,7 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                                return err;
                        }
                }
-               s->size = st.st_size;
+               s->size = xsize_t(st.st_size);
                if (!s->size)
                        goto empty;
                if (size_only)
@@ -1531,12 +1544,13 @@ static void prepare_temp_file(const char *name,
                if (S_ISLNK(st.st_mode)) {
                        int ret;
                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
+                       size_t sz = xsize_t(st.st_size);
                        if (sizeof(buf) <= st.st_size)
                                die("symlink too long: %s", name);
-                       ret = readlink(name, buf, st.st_size);
+                       ret = readlink(name, buf, sz);
                        if (ret < 0)
                                die("readlink(%s)", name);
-                       prep_temp_blob(temp, buf, st.st_size,
+                       prep_temp_blob(temp, buf, sz,
                                       (one->sha1_valid ?
                                        one->sha1 : null_sha1),
                                       (one->sha1_valid ?
@@ -1944,6 +1958,23 @@ int diff_setup_done(struct diff_options *options)
        if (options->abbrev <= 0 || 40 < options->abbrev)
                options->abbrev = 40; /* full */
 
+       /*
+        * It does not make sense to show the first hit we happened
+        * to have found.  It does not make sense not to return with
+        * exit code in such a case either.
+        */
+       if (options->quiet) {
+               options->output_format = DIFF_FORMAT_NO_OUTPUT;
+               options->exit_with_status = 1;
+       }
+
+       /*
+        * If we postprocess in diffcore, we cannot simply return
+        * upon the first hit.  We need to run diff as usual.
+        */
+       if (options->pickaxe || options->filter)
+               options->quiet = 0;
+
        return 0;
 }
 
@@ -2120,6 +2151,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                options->color_diff = options->color_diff_words = 1;
        else if (!strcmp(arg, "--no-renames"))
                options->detect_rename = 0;
+       else if (!strcmp(arg, "--exit-code"))
+               options->exit_with_status = 1;
+       else if (!strcmp(arg, "--quiet"))
+               options->quiet = 1;
        else
                return 0;
        return 1;
@@ -2158,7 +2193,7 @@ static int parse_num(const char **cp_p)
        /* user says num divided by scale and we say internally that
         * is MAX_SCORE * num / scale.
         */
-       return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
+       return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
 }
 
 int diff_scoreopt_parse(const char *opt)
@@ -2884,6 +2919,8 @@ static void diffcore_apply_filter(const char *filter)
 
 void diffcore_std(struct diff_options *options)
 {
+       if (options->quiet)
+               return;
        if (options->break_opt != -1)
                diffcore_break(options->break_opt);
        if (options->detect_rename)
@@ -2896,18 +2933,11 @@ void diffcore_std(struct diff_options *options)
                diffcore_order(options->orderfile);
        diff_resolve_rename_copy();
        diffcore_apply_filter(options->filter);
-}
 
-
-void diffcore_std_no_resolve(struct diff_options *options)
-{
-       if (options->pickaxe)
-               diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
-       if (options->orderfile)
-               diffcore_order(options->orderfile);
-       diffcore_apply_filter(options->filter);
+       options->has_changes = !!diff_queued_diff.nr;
 }
 
+
 void diff_addremove(struct diff_options *options,
                    int addremove, unsigned mode,
                    const unsigned char *sha1,
@@ -2943,6 +2973,7 @@ void diff_addremove(struct diff_options *options,
                fill_filespec(two, sha1, mode);
 
        diff_queue(&diff_queued_diff, one, two);
+       options->has_changes = 1;
 }
 
 void diff_change(struct diff_options *options,
@@ -2968,6 +2999,7 @@ void diff_change(struct diff_options *options,
        fill_filespec(two, new_sha1, new_mode);
 
        diff_queue(&diff_queued_diff, one, two);
+       options->has_changes = 1;
 }
 
 void diff_unmerge(struct diff_options *options,