am: refactor read_author_script()

By splitting the part that reads from a file and the part that
parses the variable definitions from the contents, make the latter
can be more reusable in the future.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/am.c b/builtin/am.c
index 739b34d..b36d1f0 100644 (file)
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -28,6 +28,7 @@
 #include "rerere.h"
 #include "prompt.h"
 #include "mailinfo.h"
+#include "string-list.h"
 
 /**
  * Returns 1 if the file is empty or does not exist, 0 otherwise.
@@ -258,38 +259,29 @@ static int read_state_file(struct strbuf *sb, const struct am_state *state,
 }
 
 /**
- * Reads a KEY=VALUE shell variable assignment from `fp`, returning the VALUE
- * as a newly-allocated string. VALUE must be a quoted string, and the KEY must
- * match `key`. Returns NULL on failure.
- *
- * This is used by read_author_script() to read the GIT_AUTHOR_* variables from
- * the author-script.
+ * Take a series of KEY='VALUE' lines where VALUE part is
+ * sq-quoted, and append <KEY, VALUE> at the end of the string list
  */
-static char *read_shell_var(FILE *fp, const char *key)
+static int parse_key_value_squoted(char *buf, struct string_list *list)
 {
-       struct strbuf sb = STRBUF_INIT;
-       const char *str;
-
-       if (strbuf_getline_lf(&sb, fp))
-               goto fail;
-
-       if (!skip_prefix(sb.buf, key, &str))
-               goto fail;
-
-       if (!skip_prefix(str, "=", &str))
-               goto fail;
-
-       strbuf_remove(&sb, 0, str - sb.buf);
-
-       str = sq_dequote(sb.buf);
-       if (!str)
-               goto fail;
-
-       return strbuf_detach(&sb, NULL);
-
-fail:
-       strbuf_release(&sb);
-       return NULL;
+       while (*buf) {
+               struct string_list_item *item;
+               char *np;
+               char *cp = strchr(buf, '=');
+               if (!cp)
+                       return -1;
+               np = strchrnul(cp, '\n');
+               *cp++ = '\0';
+               item = string_list_append(list, buf);
+
+               buf = np + (*np == '\n');
+               *np = '\0';
+               cp = sq_dequote(cp);
+               if (!cp)
+                       return -1;
+               item->util = xstrdup(cp);
+       }
+       return 0;
 }
 
 /**
@@ -311,44 +303,39 @@ fail:
 static int read_author_script(struct am_state *state)
 {
        const char *filename = am_path(state, "author-script");
-       FILE *fp;
+       struct strbuf buf = STRBUF_INIT;
+       struct string_list kv = STRING_LIST_INIT_DUP;
+       int retval = -1; /* assume failure */
+       int fd;
 
        assert(!state->author_name);
        assert(!state->author_email);
        assert(!state->author_date);
 
-       fp = fopen(filename, "r");
-       if (!fp) {
+       fd = open(filename, O_RDONLY);
+       if (fd < 0) {
                if (errno == ENOENT)
                        return 0;
                die_errno(_("could not open '%s' for reading"), filename);
        }
+       strbuf_read(&buf, fd, 0);
+       close(fd);
+       if (parse_key_value_squoted(buf.buf, &kv))
+               goto finish;
 
-       state->author_name = read_shell_var(fp, "GIT_AUTHOR_NAME");
-       if (!state->author_name) {
-               fclose(fp);
-               return -1;
-       }
-
-       state->author_email = read_shell_var(fp, "GIT_AUTHOR_EMAIL");
-       if (!state->author_email) {
-               fclose(fp);
-               return -1;
-       }
-
-       state->author_date = read_shell_var(fp, "GIT_AUTHOR_DATE");
-       if (!state->author_date) {
-               fclose(fp);
-               return -1;
-       }
-
-       if (fgetc(fp) != EOF) {
-               fclose(fp);
-               return -1;
-       }
-
-       fclose(fp);
-       return 0;
+       if (kv.nr != 3 ||
+           strcmp(kv.items[0].string, "GIT_AUTHOR_NAME") ||
+           strcmp(kv.items[1].string, "GIT_AUTHOR_EMAIL") ||
+           strcmp(kv.items[2].string, "GIT_AUTHOR_DATE"))
+               goto finish;
+       state->author_name = kv.items[0].util;
+       state->author_email = kv.items[1].util;
+       state->author_date = kv.items[2].util;
+       retval = 0;
+finish:
+       string_list_clear(&kv, !!retval);
+       strbuf_release(&buf);
+       return retval;
 }
 
 /**