remove stale document from malloc src directory

[oweals/musl.git] / src / stdio / getdelim.c

diff --git a/src/stdio/getdelim.c b/src/stdio/getdelim.c
index 26093a6cfa02a358c1a50e6e59ac618d8920d86e..d2f5b15ab1d7da3d693bcf5d9d4652ec89d4e858 100644 (file)
--- a/src/stdio/getdelim.c
+++ b/src/stdio/getdelim.c
@@ -1,10 +1,9 @@
 #include "stdio_impl.h"
 #include <string.h>
+#include <stdlib.h>
 #include <inttypes.h>
 #include <errno.h>
 
-#define MIN(a,b) ((a)<(b) ? (a) : (b))
-
 ssize_t getdelim(char **restrict s, size_t *restrict n, int delim, FILE *restrict f)
 {
        char *tmp;
@@ -13,29 +12,48 @@ ssize_t getdelim(char **restrict s, size_t *restrict n, int delim, FILE *restric
        size_t i=0;
        int c;
 
+       FLOCK(f);
+
        if (!n || !s) {
+               f->mode |= f->mode-1;
+               f->flags |= F_ERR;
+               FUNLOCK(f);
                errno = EINVAL;
                return -1;
        }
 
        if (!*s) *n=0;
 
-       FLOCK(f);
-
        for (;;) {
-               z = memchr(f->rpos, delim, f->rend - f->rpos);
-               k = z ? z - f->rpos + 1 : f->rend - f->rpos;
+               if (f->rpos != f->rend) {
+                       z = memchr(f->rpos, delim, f->rend - f->rpos);
+                       k = z ? z - f->rpos + 1 : f->rend - f->rpos;
+               } else {
+                       z = 0;
+                       k = 0;
+               }
                if (i+k >= *n) {
-                       if (k >= SIZE_MAX/2-i) goto oom;
-                       *n = i+k+2;
-                       if (*n < SIZE_MAX/4) *n *= 2;
-                       tmp = realloc(*s, *n);
+                       size_t m = i+k+2;
+                       if (!z && m < SIZE_MAX/4) m += m/2;
+                       tmp = realloc(*s, m);
                        if (!tmp) {
-                               *n = i+k+2;
-                               tmp = realloc(*s, *n);
-                               if (!tmp) goto oom;
+                               m = i+k+2;
+                               tmp = realloc(*s, m);
+                               if (!tmp) {
+                                       /* Copy as much as fits and ensure no
+                                        * pushback remains in the FILE buf. */
+                                       k = *n-i;
+                                       memcpy(*s+i, f->rpos, k);
+                                       f->rpos += k;
+                                       f->mode |= f->mode-1;
+                                       f->flags |= F_ERR;
+                                       FUNLOCK(f);
+                                       errno = ENOMEM;
+                                       return -1;
+                               }
                        }
                        *s = tmp;
+                       *n = m;
                }
                memcpy(*s+i, f->rpos, k);
                f->rpos += k;
@@ -48,17 +66,16 @@ ssize_t getdelim(char **restrict s, size_t *restrict n, int delim, FILE *restric
                        }
                        break;
                }
-               if (((*s)[i++] = c) == delim) break;
+               /* If the byte read by getc won't fit without growing the
+                * output buffer, push it back for next iteration. */
+               if (i+1 >= *n) *--f->rpos = c;
+               else if (((*s)[i++] = c) == delim) break;
        }
        (*s)[i] = 0;
 
        FUNLOCK(f);
 
        return i;
-oom:
-       FUNLOCK(f);
-       errno = ENOMEM;
-       return -1;
 }
 
 weak_alias(getdelim, __getdelim);