git/merge-file.c
Shawn Pearce 9befac470b Replace uses of strdup with xstrdup.
Like xmalloc and xrealloc xstrdup dies with a useful message if
the native strdup() implementation returns NULL rather than a
valid pointer.

I just tried to use xstrdup in new code and found it to be missing.
However I expected it to be present as xmalloc and xrealloc are
already commonly used throughout the code.

[jc: removed the part that deals with last_XXX, which I am
 finding more and more dubious these days.]

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-02 03:24:37 -07:00

167 lines
3.3 KiB
C

#include "cache.h"
#include "run-command.h"
#include "xdiff-interface.h"
#include "blob.h"
static void rm_temp_file(const char *filename)
{
unlink(filename);
free((void *)filename);
}
static const char *write_temp_file(mmfile_t *f)
{
int fd;
const char *tmp = getenv("TMPDIR");
char *filename;
if (!tmp)
tmp = "/tmp";
filename = mkpath("%s/%s", tmp, "git-tmp-XXXXXX");
fd = mkstemp(filename);
if (fd < 0)
return NULL;
filename = xstrdup(filename);
if (f->size != xwrite(fd, f->ptr, f->size)) {
rm_temp_file(filename);
return NULL;
}
close(fd);
return filename;
}
static void *read_temp_file(const char *filename, unsigned long *size)
{
struct stat st;
char *buf = NULL;
int fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
if (!fstat(fd, &st)) {
*size = st.st_size;
buf = xmalloc(st.st_size);
if (st.st_size != xread(fd, buf, st.st_size)) {
free(buf);
buf = NULL;
}
}
close(fd);
return buf;
}
static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
{
void *buf;
unsigned long size;
char type[20];
buf = read_sha1_file(obj->object.sha1, type, &size);
if (!buf)
return -1;
if (strcmp(type, blob_type))
return -1;
f->ptr = buf;
f->size = size;
return 0;
}
static void free_mmfile(mmfile_t *f)
{
free(f->ptr);
}
static void *three_way_filemerge(mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
{
void *res;
const char *t1, *t2, *t3;
t1 = write_temp_file(base);
t2 = write_temp_file(our);
t3 = write_temp_file(their);
res = NULL;
if (t1 && t2 && t3) {
int code = run_command("merge", t2, t1, t3, NULL);
if (!code || code == -1)
res = read_temp_file(t2, size);
}
rm_temp_file(t1);
rm_temp_file(t2);
rm_temp_file(t3);
return res;
}
static int common_outf(void *priv_, mmbuffer_t *mb, int nbuf)
{
int i;
mmfile_t *dst = priv_;
for (i = 0; i < nbuf; i++) {
memcpy(dst->ptr + dst->size, mb[i].ptr, mb[i].size);
dst->size += mb[i].size;
}
return 0;
}
static int generate_common_file(mmfile_t *res, mmfile_t *f1, mmfile_t *f2)
{
unsigned long size = f1->size < f2->size ? f1->size : f2->size;
void *ptr = xmalloc(size);
xpparam_t xpp;
xdemitconf_t xecfg;
xdemitcb_t ecb;
xpp.flags = XDF_NEED_MINIMAL;
xecfg.ctxlen = 3;
xecfg.flags = XDL_EMIT_COMMON;
ecb.outf = common_outf;
res->ptr = ptr;
res->size = 0;
ecb.priv = res;
return xdl_diff(f1, f2, &xpp, &xecfg, &ecb);
}
void *merge_file(struct blob *base, struct blob *our, struct blob *their, unsigned long *size)
{
void *res = NULL;
mmfile_t f1, f2, common;
/*
* Removed in either branch?
*
* NOTE! This depends on the caller having done the
* proper warning about removing a file that got
* modified in the other branch!
*/
if (!our || !their) {
char type[20];
if (base)
return NULL;
if (!our)
our = their;
return read_sha1_file(our->object.sha1, type, size);
}
if (fill_mmfile_blob(&f1, our) < 0)
goto out_no_mmfile;
if (fill_mmfile_blob(&f2, their) < 0)
goto out_free_f1;
if (base) {
if (fill_mmfile_blob(&common, base) < 0)
goto out_free_f2_f1;
} else {
if (generate_common_file(&common, &f1, &f2) < 0)
goto out_free_f2_f1;
}
res = three_way_filemerge(&common, &f1, &f2, size);
free_mmfile(&common);
out_free_f2_f1:
free_mmfile(&f2);
out_free_f1:
free_mmfile(&f1);
out_no_mmfile:
return res;
}