c = getc(f1); if (c < 0)
if ((c = getc(f1)) == EOF)
output(char *file1, FILE *f1, char *file2, FILE *f2){	int m, i0, i1, j0, j1;	rewind(f1);	rewind(f2);	m = len[0];	J[0] = 0;	J[m + 1] = len[1] + 1;	if (format != D_EDIT) {		for (i0 = 1; i0 <= m; i0 = i1 + 1) {			while (i0 <= m && J[i0] == J[i0 - 1] + 1)				i0++;			j0 = J[i0 - 1] + 1;			i1 = i0 - 1;			while (i1 < m && J[i1 + 1] == 0)				i1++;			j1 = J[i1 + 1] - 1;			J[i1] = j1;			change(file1, f1, file2, f2, i0, i1, j0, j1);		}	} else {		for (i0 = m; i0 >= 1; i0 = i1 - 1) {			while (i0 >= 1 && J[i0] == J[i0 + 1] - 1 && J[i0] != 0)				i0--;			j0 = J[i0 + 1] - 1;			i1 = i0 + 1;			while (i1 > 1 && J[i1 - 1] == 0)				i1--;			j1 = J[i1 - 1] + 1;			J[i1] = j1;			change(file1, f1, file2, f2, i1, i0, j1, j0);		}	}	if (m == 0)		change(file1, f1, file2, f2, 1, 0, 1, len[1]);	if (format == D_IFDEF) {		for (;;) {#define	c i0			c = getc(f1);			if (c < 0)				return;			putchar(c);		}#undef c	}	if (anychange != 0) {		if (format == D_CONTEXT)			dump_context_vec(f1, f2);		else if (format == D_UNIFIED)			dump_unified_vec(f1, f2);	}}