cleanup: use internal memory allocation wrapper functions everywhere

The "x"-prefixed versions of strdup, malloc, etc. will check whether the
allocation was successful and terminate the process otherwise.

A few uses of malloc were left alone since they already implemented a
graceful path of failure or were in a quasi external library like xdiff.

Additionally, the call to malloc in compat/win32/syslog.c was not modified
since the syslog() implemented there is a die handler and a call to the
x-wrappers within a die handler could result in recursion should memory
allocation fail.  This will have to be addressed separately.

Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

attr.c

@@ -533,7 +533,7 @@ static void bootstrap_attr_stack(void)
 
 		if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 			elem = read_attr(GITATTRIBUTES_FILE, 1);
-			elem->origin = strdup("");
+			elem->origin = xstrdup("");
 			elem->prev = attr_stack;
 			attr_stack = elem;
 			debug_push(elem);

builtin/mv.c

@@ -29,7 +29,7 @@ static const char **copy_pathspec(const char *prefix, const char **pathspec,
 			to_copy--;
 		if (to_copy != length || base_name) {
 			char *it = xmemdupz(result[i], to_copy);
-			result[i] = base_name ? strdup(basename(it)) : it;
+			result[i] = base_name ? xstrdup(basename(it)) : it;
 		}
 	}
 	return get_pathspec(prefix, result);

compat/mingw.c

@@ -1183,7 +1183,7 @@ static int WSAAPI getaddrinfo_stub(const char *node, const char *service,
 	}
 	ai->ai_addrlen = sizeof(struct sockaddr_in);
 	if (hints && (hints->ai_flags & AI_CANONNAME))
-		ai->ai_canonname = h ? strdup(h->h_name) : NULL;
+		ai->ai_canonname = h ? xstrdup(h->h_name) : NULL;
 	else
 		ai->ai_canonname = NULL;
 

compat/qsort.c

@@ -55,7 +55,7 @@ void git_qsort(void *b, size_t n, size_t s,
 		msort_with_tmp(b, n, s, cmp, buf);
 	} else {
 		/* It's somewhat large, so malloc it.  */
-		char *tmp = malloc(size);
+		char *tmp = xmalloc(size);
 		msort_with_tmp(b, n, s, cmp, tmp);
 		free(tmp);
 	}

remote.c

@@ -840,7 +840,7 @@ char *apply_refspecs(struct refspec *refspecs, int nr_refspec,
 						    refspec->dst, &ret))
 				return ret;
 		} else if (!strcmp(refspec->src, name))
-			return strdup(refspec->dst);
+			return xstrdup(refspec->dst);
 	}
 	return NULL;
 }

show-index.c

@@ -48,7 +48,7 @@ int main(int argc, char **argv)
 			unsigned char sha1[20];
 			uint32_t crc;
 			uint32_t off;
-		} *entries = malloc(nr * sizeof(entries[0]));
+		} *entries = xmalloc(nr * sizeof(entries[0]));
 		for (i = 0; i < nr; i++)
 			if (fread(entries[i].sha1, 20, 1, stdin) != 1)
 				die("unable to read sha1 %u/%u", i, nr);

transport-helper.c

@@ -183,7 +183,7 @@ static struct child_process *get_helper(struct transport *transport)
 			ALLOC_GROW(refspecs,
 				   refspec_nr + 1,
 				   refspec_alloc);
-			refspecs[refspec_nr++] = strdup(capname + strlen("refspec "));
+			refspecs[refspec_nr++] = xstrdup(capname + strlen("refspec "));
 		} else if (!strcmp(capname, "connect")) {
 			data->connect = 1;
 		} else if (!prefixcmp(capname, "export-marks ")) {
@@ -445,7 +445,7 @@ static int fetch_with_import(struct transport *transport,
 		if (data->refspecs)
 			private = apply_refspecs(data->refspecs, data->refspec_nr, posn->name);
 		else
-			private = strdup(posn->name);
+			private = xstrdup(posn->name);
 		read_ref(private, posn->old_sha1);
 		free(private);
 	}