From b6ade08beedcfa4c01d642ee383618b22ab09b45 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Thu, 1 May 2008 16:49:21 +0200
Subject: [PATCH] Fix computation of newsize during reallocation.
---
ChangeLog | 5 +++++
lib/getndelim2.c | 21 ++++++++++++++-------
2 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 03e2df7405..f3b5bf9361 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-05-01 Bruno Haible <bruno@clisp.org>
+
+ * lib/getndelim2.c (getndelim2): Fix newsize computation during
+ reallocation. Rename 'done' to 'found_delimiter'.
+
2008-05-01 Jim Meyering <meyering@redhat.com>
vc-list-files: accommodate /bin/sh like the one from Solaris 10
diff --git a/lib/getndelim2.c b/lib/getndelim2.c
index 04349ad7e9..9dcb9feb46 100644
--- a/lib/getndelim2.c
+++ b/lib/getndelim2.c
@@ -76,7 +76,7 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
ssize_t bytes_stored = -1;
char *ptr = *lineptr;
size_t size = *linesize;
- bool done = false;
+ bool found_delimiter;
if (!ptr)
{
@@ -103,7 +103,8 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
flockfile (stream);
- while (!done)
+ found_delimiter = false;
+ do
{
/* Here always ptr + size == read_pos + nbytes_avail.
Also nbytes_avail > 0 || size < nmax. */
@@ -121,7 +122,7 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
if (end)
{
buffer_len = end - buffer + 1;
- done = true;
+ found_delimiter = true;
}
}
}
@@ -137,7 +138,7 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
break;
}
if (c == delim1 || c == delim2)
- done = true;
+ found_delimiter = true;
buffer_len = 1;
}
@@ -145,13 +146,18 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
always (unless we get an error while reading the first byte)
NUL-terminate the line buffer. */
- if (nbytes_avail < 1 + buffer_len && size < nmax)
+ if (nbytes_avail < buffer_len + 1 && size < nmax)
{
+ /* Grow size proportionally, not linearly, to avoid O(n^2)
+ running time. */
size_t newsize = size < MIN_CHUNK ? size + MIN_CHUNK : 2 * size;
char *newptr;
- if (newsize < buffer_len)
- newsize = buffer_len + size;
+ /* Increase newsize so that it becomes
+ >= (read_pos - ptr) + buffer_len. */
+ if (newsize - (read_pos - ptr) < buffer_len + 1)
+ newsize = (read_pos - ptr) + buffer_len + 1;
+ /* Respect nmax. This handles possible integer overflow. */
if (! (size < newsize && newsize <= nmax))
newsize = nmax;
@@ -193,6 +199,7 @@ getndelim2 (char **lineptr, size_t *linesize, size_t offset, size_t nmax,
if (buffer && freadseek (stream, buffer_len))
goto unlock_done;
}
+ while (!found_delimiter);
/* Done - NUL terminate and return the number of bytes read.
At this point we know that nbytes_avail >= 1. */
--
2.30.2