diff-no-index: DWIM "diff D F" into "diff D/F F"

diff --git a/diff-no-index.c b/diff-no-index.c
index 798477f7e5b19e3141bd8a1e63bc650f13ad2e39..49c4536d1d2bee8ffe463966e8783f0195562738 100644 (file)
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -15,8 +15,9 @@
 #include "log-tree.h"
 #include "builtin.h"
 #include "string-list.h"
+#include "dir.h"
 
-static int read_directory(const char *path, struct string_list *list)
+static int read_directory_contents(const char *path, struct string_list *list)
 {
        DIR *dir;
        struct dirent *e;
@@ -25,7 +26,7 @@ static int read_directory(const char *path, struct string_list *list)
                return error("Could not open directory %s", path);
 
        while ((e = readdir(dir)))
-               if (strcmp(".", e->d_name) && strcmp("..", e->d_name))
+               if (!is_dot_or_dotdot(e->d_name))
                        string_list_insert(list, e->d_name);
 
        closedir(dir);
@@ -107,9 +108,9 @@ static int queue_diff(struct diff_options *o,
                int i1, i2, ret = 0;
                size_t len1 = 0, len2 = 0;
 
-               if (name1 && read_directory(name1, &p1))
+               if (name1 && read_directory_contents(name1, &p1))
                        return -1;
-               if (name2 && read_directory(name2, &p2)) {
+               if (name2 && read_directory_contents(name2, &p2)) {
                        string_list_clear(&p1, 0);
                        return -1;
                }
@@ -181,23 +182,56 @@ static int queue_diff(struct diff_options *o,
        }
 }
 
+/* append basename of F to D */
+static void append_basename(struct strbuf *path, const char *dir, const char *file)
+{
+       const char *tail = strrchr(file, '/');
+
+       strbuf_addstr(path, dir);
+       while (path->len && path->buf[path->len - 1] == '/')
+               path->len--;
+       strbuf_addch(path, '/');
+       strbuf_addstr(path, tail ? tail + 1 : file);
+}
+
+/*
+ * DWIM "diff D F" into "diff D/F F" and "diff F D" into "diff F D/F"
+ * Note that we append the basename of F to D/, so "diff a/b/file D"
+ * becomes "diff a/b/file D/file", not "diff a/b/file D/a/b/file".
+ */
+static void fixup_paths(const char **path, struct strbuf *replacement)
+{
+       unsigned int isdir0, isdir1;
+
+       if (path[0] == file_from_standard_input ||
+           path[1] == file_from_standard_input)
+               return;
+       isdir0 = is_directory(path[0]);
+       isdir1 = is_directory(path[1]);
+       if (isdir0 == isdir1)
+               return;
+       if (isdir0) {
+               append_basename(replacement, path[0], path[1]);
+               path[0] = replacement->buf;
+       } else {
+               append_basename(replacement, path[1], path[0]);
+               path[1] = replacement->buf;
+       }
+}
+
 void diff_no_index(struct rev_info *revs,
                   int argc, const char **argv,
                   const char *prefix)
 {
        int i, prefixlen;
-       unsigned deprecated_show_diff_q_option_used = 0;
        const char *paths[2];
+       struct strbuf replacement = STRBUF_INIT;
 
        diff_setup(&revs->diffopt);
        for (i = 1; i < argc - 2; ) {
                int j;
                if (!strcmp(argv[i], "--no-index"))
                        i++;
-               else if (!strcmp(argv[i], "-q")) {
-                       deprecated_show_diff_q_option_used = 1;
-                       i++;
-               }
                else if (!strcmp(argv[i], "--"))
                        i++;
                else {
@@ -221,6 +255,9 @@ void diff_no_index(struct rev_info *revs,
                        p = xstrdup(prefix_filename(prefix, prefixlen, p));
                paths[i] = p;
        }
+
+       fixup_paths(paths, &replacement);
+
        revs->diffopt.skip_stat_unmatch = 1;
        if (!revs->diffopt.output_format)
                revs->diffopt.output_format = DIFF_FORMAT_PATCH;
@@ -230,9 +267,6 @@ void diff_no_index(struct rev_info *revs,
        revs->max_count = -2;
        diff_setup_done(&revs->diffopt);
 
-       if (deprecated_show_diff_q_option_used)
-               handle_deprecated_show_diff_q(&revs->diffopt);
-
        setup_diff_pager(&revs->diffopt);
        DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
 
@@ -242,6 +276,8 @@ void diff_no_index(struct rev_info *revs,
        diffcore_std(&revs->diffopt);
        diff_flush(&revs->diffopt);
 
+       strbuf_release(&replacement);
+
        /*
         * The return code for --no-index imitates diff(1):
         * 0 = no changes, 1 = changes, else error