fetch: don't redundantly NULL something calloc() gave us

diff --git a/grep.c b/grep.c
index d0b9b6cdfa74537ed67dcfef4ae486466d7185f8..3d7cd0e96f1ee160a66dd500c58d4026bf24e34c 100644 (file)
--- a/grep.c
+++ b/grep.c
@@ -477,6 +477,8 @@ static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt
        int options = PCRE2_MULTILINE;
        const uint8_t *character_tables = NULL;
        int jitret;
+       int patinforet;
+       size_t jitsizearg;
 
        assert(opt->pcre2);
 
@@ -511,6 +513,30 @@ static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt
                jitret = pcre2_jit_compile(p->pcre2_pattern, PCRE2_JIT_COMPLETE);
                if (jitret)
                        die("Couldn't JIT the PCRE2 pattern '%s', got '%d'\n", p->pattern, jitret);
+
+               /*
+                * The pcre2_config(PCRE2_CONFIG_JIT, ...) call just
+                * tells us whether the library itself supports JIT,
+                * but to see whether we're going to be actually using
+                * JIT we need to extract PCRE2_INFO_JITSIZE from the
+                * pattern *after* we do pcre2_jit_compile() above.
+                *
+                * This is because if the pattern contains the
+                * (*NO_JIT) verb (see pcre2syntax(3))
+                * pcre2_jit_compile() will exit early with 0. If we
+                * then proceed to call pcre2_jit_match() further down
+                * the line instead of pcre2_match() we'll either
+                * segfault (pre PCRE 10.31) or run into a fatal error
+                * (post PCRE2 10.31)
+                */
+               patinforet = pcre2_pattern_info(p->pcre2_pattern, PCRE2_INFO_JITSIZE, &jitsizearg);
+               if (patinforet)
+                       BUG("pcre2_pattern_info() failed: %d", patinforet);
+               if (jitsizearg == 0) {
+                       p->pcre2_jit_on = 0;
+                       return;
+               }
+
                p->pcre2_jit_stack = pcre2_jit_stack_create(1, 1024 * 1024, NULL);
                if (!p->pcre2_jit_stack)
                        die("Couldn't allocate PCRE2 JIT stack");
@@ -1476,31 +1502,52 @@ static void show_funcname_line(struct grep_opt *opt, struct grep_source *gs,
        }
 }
 
+static int is_empty_line(const char *bol, const char *eol);
+
 static void show_pre_context(struct grep_opt *opt, struct grep_source *gs,
                             char *bol, char *end, unsigned lno)
 {
-       unsigned cur = lno, from = 1, funcname_lno = 0;
-       int funcname_needed = !!opt->funcname;
-
-       if (opt->funcbody && !match_funcname(opt, gs, bol, end))
-               funcname_needed = 2;
+       unsigned cur = lno, from = 1, funcname_lno = 0, orig_from;
+       int funcname_needed = !!opt->funcname, comment_needed = 0;
 
        if (opt->pre_context < lno)
                from = lno - opt->pre_context;
        if (from <= opt->last_shown)
                from = opt->last_shown + 1;
+       orig_from = from;
+       if (opt->funcbody) {
+               if (match_funcname(opt, gs, bol, end))
+                       comment_needed = 1;
+               else
+                       funcname_needed = 1;
+               from = opt->last_shown + 1;
+       }
 
        /* Rewind. */
-       while (bol > gs->buf &&
-              cur > (funcname_needed == 2 ? opt->last_shown + 1 : from)) {
+       while (bol > gs->buf && cur > from) {
+               char *next_bol = bol;
                char *eol = --bol;
 
                while (bol > gs->buf && bol[-1] != '\n')
                        bol--;
                cur--;
+               if (comment_needed && (is_empty_line(bol, eol) ||
+                                      match_funcname(opt, gs, bol, eol))) {
+                       comment_needed = 0;
+                       from = orig_from;
+                       if (cur < from) {
+                               cur++;
+                               bol = next_bol;
+                               break;
+                       }
+               }
                if (funcname_needed && match_funcname(opt, gs, bol, eol)) {
                        funcname_lno = cur;
                        funcname_needed = 0;
+                       if (opt->funcbody)
+                               comment_needed = 1;
+                       else
+                               from = orig_from;
                }
        }