contrib: add 'git difftool' for launching common merge tools

diff --git a/strbuf.c b/strbuf.c
index bdf49544d47b97475800b104ed9efe8f846db265..6ed06840b856a91f6d215c9a862e064f521384f0 100644 (file)
--- a/strbuf.c
+++ b/strbuf.c
@@ -256,18 +256,21 @@ size_t strbuf_expand_dict_cb(struct strbuf *sb, const char *placeholder,
 size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 {
        size_t res;
+       size_t oldalloc = sb->alloc;
 
        strbuf_grow(sb, size);
        res = fread(sb->buf + sb->len, 1, size, f);
-       if (res > 0) {
+       if (res > 0)
                strbuf_setlen(sb, sb->len + res);
-       }
+       else if (res < 0 && oldalloc == 0)
+               strbuf_release(sb);
        return res;
 }
 
 ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 {
        size_t oldlen = sb->len;
+       size_t oldalloc = sb->alloc;
 
        strbuf_grow(sb, hint ? hint : 8192);
        for (;;) {
@@ -275,7 +278,10 @@ ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 
                cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
                if (cnt < 0) {
-                       strbuf_setlen(sb, oldlen);
+                       if (oldalloc == 0)
+                               strbuf_release(sb);
+                       else
+                               strbuf_setlen(sb, oldlen);
                        return -1;
                }
                if (!cnt)
@@ -292,6 +298,8 @@ ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 
 int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
 {
+       size_t oldalloc = sb->alloc;
+
        if (hint < 32)
                hint = 32;
 
@@ -311,7 +319,8 @@ int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
                /* .. the buffer was too small - try again */
                hint *= 2;
        }
-       strbuf_release(sb);
+       if (oldalloc == 0)
+               strbuf_release(sb);
        return -1;
 }