Update git-diff-* to use C-style quoting for funny pathnames.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/diff.c b/diff.c
index cbb8632..823c8d0 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -13,6 +13,46 @@ static const char *diff_opts = "-pu";
 
 static int use_size_cache;
 
+static char *quote_one(const char *str)
+{
+       int needlen;
+       char *xp;
+
+       if (!str)
+               return NULL;
+       needlen = quote_c_style(str, NULL, NULL, 0);
+       if (!needlen)
+               return strdup(str);
+       xp = xmalloc(needlen + 1);
+       quote_c_style(str, xp, NULL, 0);
+       return xp;
+}
+
+static char *quote_two(const char *one, const char *two)
+{
+       int need_one = quote_c_style(one, NULL, NULL, 1);
+       int need_two = quote_c_style(two, NULL, NULL, 1);
+       char *xp;
+
+       if (need_one + need_two) {
+               if (!need_one) need_one = strlen(one);
+               if (!need_two) need_one = strlen(two);
+
+               xp = xmalloc(need_one + need_two + 3);
+               xp[0] = '"';
+               quote_c_style(one, xp + 1, NULL, 1);
+               quote_c_style(two, xp + need_one + 1, NULL, 1);
+               strcpy(xp + need_one + need_two + 1, "\"");
+               return xp;
+       }
+       need_one = strlen(one);
+       need_two = strlen(two);
+       xp = xmalloc(need_one + need_two + 1);
+       strcpy(xp, one);
+       strcpy(xp + need_one, two);
+       return xp;
+}
+
 static const char *external_diff(void)
 {
        static const char *external_diff_cmd = NULL;
@@ -133,55 +173,52 @@ static void builtin_diff(const char *name_a,
                         int complete_rewrite)
 {
        int i, next_at, cmd_size;
-       const char *const diff_cmd = "diff -L%s%s -L%s%s";
+       const char *const diff_cmd = "diff -L%s -L%s";
        const char *const diff_arg  = "%s %s||:"; /* "||:" is to return 0 */
        const char *input_name_sq[2];
-       const char *path0[2];
-       const char *path1[2];
-       const char *name_sq[2];
+       const char *label_path[2];
        char *cmd;
 
-       name_sq[0] = sq_quote(name_a);
-       name_sq[1] = sq_quote(name_b);
-
-       /* diff_cmd and diff_arg have 6 %s in total which makes
-        * the sum of these strings 12 bytes larger than required.
+       /* diff_cmd and diff_arg have 4 %s in total which makes
+        * the sum of these strings 8 bytes larger than required.
         * we use 2 spaces around diff-opts, and we need to count
-        * terminating NUL, so we subtract 9 here.
+        * terminating NUL; we used to subtract 5 here, but we do not
+        * care about small leaks in this subprocess that is about
+        * to exec "diff" anymore.
         */
-       cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
-                       strlen(diff_arg) - 9);
+       cmd_size = (strlen(diff_cmd) + strlen(diff_opts) + strlen(diff_arg)
+                   + 128);
+
        for (i = 0; i < 2; i++) {
                input_name_sq[i] = sq_quote(temp[i].name);
-               if (!strcmp(temp[i].name, "/dev/null")) {
-                       path0[i] = "/dev/null";
-                       path1[i] = "";
-               } else {
-                       path0[i] = i ? "b/" : "a/";
-                       path1[i] = name_sq[i];
-               }
-               cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
-                            strlen(input_name_sq[i]));
+               if (!strcmp(temp[i].name, "/dev/null"))
+                       label_path[i] = "/dev/null";
+               else if (!i)
+                       label_path[i] = sq_quote(quote_two("a/", name_a));
+               else
+                       label_path[i] = sq_quote(quote_two("b/", name_b));
+               cmd_size += (strlen(label_path[i]) + strlen(input_name_sq[i]));
        }
 
        cmd = xmalloc(cmd_size);
 
        next_at = 0;
        next_at += snprintf(cmd+next_at, cmd_size-next_at,
-                           diff_cmd,
-                           path0[0], path1[0], path0[1], path1[1]);
+                           diff_cmd, label_path[0], label_path[1]);
        next_at += snprintf(cmd+next_at, cmd_size-next_at,
                            " %s ", diff_opts);
        next_at += snprintf(cmd+next_at, cmd_size-next_at,
                            diff_arg, input_name_sq[0], input_name_sq[1]);
 
-       printf("diff --git a/%s b/%s\n", name_a, name_b);
-       if (!path1[0][0]) {
+       printf("diff --git %s %s\n",
+              quote_two("a/", name_a), quote_two("b/", name_b));
+       if (label_path[0][0] == '/') {
+               /* dev/null */
                printf("new file mode %s\n", temp[1].mode);
                if (xfrm_msg && xfrm_msg[0])
                        puts(xfrm_msg);
        }
-       else if (!path1[1][0]) {
+       else if (label_path[1][0] == '/') {
                printf("deleted file mode %s\n", temp[0].mode);
                if (xfrm_msg && xfrm_msg[0])
                        puts(xfrm_msg);
@@ -619,6 +656,7 @@ static void run_diff(struct diff_filepair *p)
        struct diff_filespec *two;
        const char *name;
        const char *other;
+       char *name_munged, *other_munged;
        int complete_rewrite = 0;
        int len;
 
@@ -631,6 +669,8 @@ static void run_diff(struct diff_filepair *p)
 
        name = p->one->path;
        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+       name_munged = quote_one(name);
+       other_munged = quote_one(other);
        one = p->one; two = p->two;
 
        diff_fill_sha1_info(one);
@@ -644,7 +684,7 @@ static void run_diff(struct diff_filepair *p)
                                "copy from %s\n"
                                "copy to %s\n",
                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
-                               name, other);
+                               name_munged, other_munged);
                break;
        case DIFF_STATUS_RENAMED:
                len += snprintf(msg + len, sizeof(msg) - len,
@@ -652,7 +692,7 @@ static void run_diff(struct diff_filepair *p)
                                "rename from %s\n"
                                "rename to %s\n",
                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
-                               name, other);
+                               name_munged, other_munged);
                break;
        case DIFF_STATUS_MODIFIED:
                if (p->score) {
@@ -702,6 +742,9 @@ static void run_diff(struct diff_filepair *p)
        else
                run_external_diff(pgm, name, other, one, two, xfrm_msg,
                                  complete_rewrite);
+
+       free(name_munged);
+       free(other_munged);
 }
 
 void diff_setup(struct diff_options *options)
@@ -878,16 +921,13 @@ static void diff_flush_raw(struct diff_filepair *p,
 {
        int two_paths;
        char status[10];
+       const char *path_one, *path_two;
 
+       path_one = p->one->path;
+       path_two = p->two->path;
        if (line_termination) {
-               const char *const err =
-                       "path %s cannot be expressed without -z";
-               if (strchr(p->one->path, line_termination) ||
-                   strchr(p->one->path, inter_name_termination))
-                       die(err, p->one->path);
-               if (strchr(p->two->path, line_termination) ||
-                   strchr(p->two->path, inter_name_termination))
-                       die(err, p->two->path);
+               path_one = quote_one(path_one);
+               path_two = quote_one(path_two);
        }
 
        if (p->score)
@@ -915,16 +955,29 @@ static void diff_flush_raw(struct diff_filepair *p,
                       p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
                printf("%s ", sha1_to_hex(p->two->sha1));
        }
-       printf("%s%c%s",status, inter_name_termination, p->one->path);
+       printf("%s%c%s", status, inter_name_termination, path_one);
        if (two_paths)
-               printf("%c%s", inter_name_termination, p->two->path);
+               printf("%c%s", inter_name_termination, path_two);
        putchar(line_termination);
+       if (path_one != p->one->path)
+               free((void*)path_one);
+       if (path_two != p->two->path)
+               free((void*)path_two);
 }
 
 static void diff_flush_name(struct diff_filepair *p,
+                           int inter_name_termination,
                            int line_termination)
 {
-       printf("%s%c", p->two->path, line_termination);
+       char *path = p->two->path;
+
+       if (line_termination)
+               path = quote_one(p->two->path);
+       else
+               path = p->two->path;
+       printf("%s%c", path, line_termination);
+       if (p->two->path != path)
+               free(path);
 }
 
 int diff_unmodified_pair(struct diff_filepair *p)
@@ -1111,7 +1164,9 @@ void diff_flush(struct diff_options *options)
                                       diff_output_format);
                        break;
                case DIFF_FORMAT_NAME:
-                       diff_flush_name(p, line_termination);
+                       diff_flush_name(p,
+                                       inter_name_termination,
+                                       line_termination);
                        break;
                }
                diff_free_filepair(q->queue[i]);