lib: printf_format_fix*() - Move minimum field width check to its own function

diff --git a/src/lib/printf-format-fix.c b/src/lib/printf-format-fix.c
index ab82b5c22d738de48a6210abbf00f9960e571992..bea65b1759a89dddf8d08fdde29b48c162d89eaf 100644 (file)
--- a/src/lib/printf-format-fix.c
+++ b/src/lib/printf-format-fix.c
@@ -32,6 +32,27 @@ fix_format_real(const char *fmt, const char *p, size_t *len_r)
        return buf;
 }
 
+static bool verify_length(const char **p)
+{
+       if (**p == '*') {
+               /* We don't bother supporting "*m$" - it's not used
+                  anywhere and seems a bit dangerous. */
+               *p += 1;
+       } else if (**p >= '1' && **p <= '9') {
+               /* Limit to 4 digits - we'll never want more than that.
+                  Some implementations might not handle long digits
+                  correctly, or maybe even could be used for DoS due
+                  to using too much CPU. */
+               unsigned int i = 0;
+               do {
+                       *p += 1;
+                       if (++i > 4)
+                               return FALSE;
+               } while (**p >= '0' && **p <= '9');
+       }
+       return TRUE;
+}
+
 static const char *
 printf_format_fix_noalloc(const char *format, size_t *len_r)
 {
@@ -83,23 +104,9 @@ printf_format_fix_noalloc(const char *format, size_t *len_r)
                }
 
                /* 2) Optional minimum field width */
-               if (*p == '*') {
-                       /* We don't bother supporting "*m$" - it's not used
-                          anywhere and seems a bit dangerous. */
-                       p++;
-               } else if (*p >= '1' && *p <= '9') {
-                       /* Limit to 4 digits - we'll never want more than that.
-                          Some implementations might not handle long digits
-                          correctly, or maybe even could be used for DoS due
-                          to using too much CPU. */
-                       unsigned int i = 0;
-                       do {
-                               p++;
-                               if (++i > 4) {
-                                       i_panic("Too large minimum field width starting at #%u in '%s'",
-                                               start_pos, format);
-                               }
-                       } while (*p >= '0' && *p <= '9');
+               if (!verify_length(&p)) {
+                       i_panic("Too large minimum field width starting at #%u in '%s'",
+                               start_pos, format);
                }
 
                /* 3) Optional precision */