Rework unquote_c_style to work on a strbuf.
[gitweb.git] / quote.c
diff --git a/quote.c b/quote.c
index d88bf7515932bba96c694478c3b51c85549fa92a..7771c9c678d1b1508ef2d582eb218e57e3caeec1 100644 (file)
--- a/quote.c
+++ b/quote.c
@@ -239,73 +239,71 @@ int quote_c_style(const char *name, char *outbuf, FILE *outfp, int no_dq)
 /*
  * C-style name unquoting.
  *
- * Quoted should point at the opening double quote.  Returns
- * an allocated memory that holds unquoted name, which the caller
- * should free when done.  Updates endp pointer to point at
- * one past the ending double quote if given.
+ * Quoted should point at the opening double quote.
+ * + Returns 0 if it was able to unquote the string properly, and appends the
+ *   result in the strbuf `sb'.
+ * + Returns -1 in case of error, and doesn't touch the strbuf. Though note
+ *   that this function will allocate memory in the strbuf, so calling
+ *   strbuf_release is mandatory whichever result unquote_c_style returns.
+ *
+ * Updates endp pointer to point at one past the ending double quote if given.
  */
-
-char *unquote_c_style(const char *quoted, const char **endp)
+int unquote_c_style(struct strbuf *sb, const char *quoted, const char **endp)
 {
-       const char *sp;
-       char *name = NULL, *outp = NULL;
-       int count = 0, ch, ac;
-
-#undef EMIT
-#define EMIT(c) (outp ? (*outp++ = (c)) : (count++))
+       size_t oldlen = sb->len, len;
+       int ch, ac;
 
        if (*quoted++ != '"')
-               return NULL;
+               return -1;
+
+       for (;;) {
+               len = strcspn(quoted, "\"\\");
+               strbuf_add(sb, quoted, len);
+               quoted += len;
 
-       while (1) {
-               /* first pass counts and allocates, second pass fills */
-               for (sp = quoted; (ch = *sp++) != '"'; ) {
-                       if (ch == '\\') {
-                               switch (ch = *sp++) {
-                               case 'a': ch = '\a'; break;
-                               case 'b': ch = '\b'; break;
-                               case 'f': ch = '\f'; break;
-                               case 'n': ch = '\n'; break;
-                               case 'r': ch = '\r'; break;
-                               case 't': ch = '\t'; break;
-                               case 'v': ch = '\v'; break;
-
-                               case '\\': case '"':
-                                       break; /* verbatim */
-
-                               case '0':
-                               case '1':
-                               case '2':
-                               case '3':
-                               case '4':
-                               case '5':
-                               case '6':
-                               case '7':
-                                       /* octal */
+               switch (*quoted++) {
+                 case '"':
+                       if (endp)
+                               *endp = quoted + 1;
+                       return 0;
+                 case '\\':
+                       break;
+                 default:
+                       goto error;
+               }
+
+               switch ((ch = *quoted++)) {
+               case 'a': ch = '\a'; break;
+               case 'b': ch = '\b'; break;
+               case 'f': ch = '\f'; break;
+               case 'n': ch = '\n'; break;
+               case 'r': ch = '\r'; break;
+               case 't': ch = '\t'; break;
+               case 'v': ch = '\v'; break;
+
+               case '\\': case '"':
+                       break; /* verbatim */
+
+               /* octal values with first digit over 4 overflow */
+               case '0': case '1': case '2': case '3':
                                        ac = ((ch - '0') << 6);
-                                       if ((ch = *sp++) < '0' || '7' < ch)
-                                               return NULL;
+                       if ((ch = *quoted++) < '0' || '7' < ch)
+                               goto error;
                                        ac |= ((ch - '0') << 3);
-                                       if ((ch = *sp++) < '0' || '7' < ch)
-                                               return NULL;
+                       if ((ch = *quoted++) < '0' || '7' < ch)
+                               goto error;
                                        ac |= (ch - '0');
                                        ch = ac;
                                        break;
                                default:
-                                       return NULL; /* malformed */
-                               }
+                       goto error;
                        }
-                       EMIT(ch);
+               strbuf_addch(sb, ch);
                }
 
-               if (name) {
-                       *outp = 0;
-                       if (endp)
-                               *endp = sp;
-                       return name;
-               }
-               outp = name = xmalloc(count + 1);
-       }
+  error:
+       strbuf_setlen(sb, oldlen);
+       return -1;
 }
 
 void write_name_quoted(const char *prefix, int prefix_len,