t/README: justify why "! grep foo" is sufficient

diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index 63722f86dca4c00389d6f305fd8aa1af8ef8ed6c..401eb72c619d432c92fc66b470fae778117bcace 100644 (file)
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c
@@ -122,7 +122,7 @@ static void diffcore_pickaxe_grep(struct diff_options *o)
                char errbuf[1024];
                regerror(err, &regex, errbuf, 1024);
                regfree(&regex);
-               die("invalid log-grep regex: %s", errbuf);
+               die("invalid regex: %s", errbuf);
        }
 
        pickaxe(&diff_queued_diff, o, &regex, NULL, diff_grep);
@@ -131,8 +131,7 @@ static void diffcore_pickaxe_grep(struct diff_options *o)
        return;
 }
 
-static unsigned int contains(mmfile_t *mf, struct diff_options *o,
-                            regex_t *regexp, kwset_t kws)
+static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws)
 {
        unsigned int cnt;
        unsigned long sz;
@@ -176,11 +175,9 @@ static int has_changes(mmfile_t *one, mmfile_t *two,
                       struct diff_options *o,
                       regex_t *regexp, kwset_t kws)
 {
-       if (!one)
-               return contains(two, o, regexp, kws) != 0;
-       if (!two)
-               return contains(one, o, regexp, kws) != 0;
-       return contains(one, o, regexp, kws) != contains(two, o, regexp, kws);
+       unsigned int one_contains = one ? contains(one, regexp, kws) : 0;
+       unsigned int two_contains = two ? contains(two, regexp, kws) : 0;
+       return one_contains != two_contains;
 }
 
 static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,
@@ -246,7 +243,7 @@ static void diffcore_pickaxe_count(struct diff_options *o)
                        char errbuf[1024];
                        regerror(err, &regex, errbuf, 1024);
                        regfree(&regex);
-                       die("invalid pickaxe regex: %s", errbuf);
+                       die("invalid regex: %s", errbuf);
                }
                regexp = &regex;
        } else {