sha1_file.c: cleanup hdr usage

diff --git a/builtin-mailinfo.c b/builtin-mailinfo.c
index a67f3eb90b6f715714c6fa7bb931044630c74111..766a37ebe2da56f92be3927d6ddfe46dba9386df 100644 (file)
--- a/builtin-mailinfo.c
+++ b/builtin-mailinfo.c
@@ -406,6 +406,11 @@ static int is_rfc2822_header(char *line)
         */
        int ch;
        char *cp = line;
+
+       /* Count mbox From headers as headers */
+       if (!memcmp(line, "From ", 5) || !memcmp(line, ">From ", 6))
+               return 1;
+
        while ((ch = *cp++)) {
                if (ch == ':')
                        return cp != line;
@@ -417,30 +422,61 @@ static int is_rfc2822_header(char *line)
        return 0;
 }
 
+/*
+ * sz is size of 'line' buffer in bytes.  Must be reasonably
+ * long enough to hold one physical real-world e-mail line.
+ */
 static int read_one_header_line(char *line, int sz, FILE *in)
 {
-       int ofs = 0;
-       while (ofs < sz) {
-               int peek, len;
-               if (fgets(line + ofs, sz - ofs, in) == NULL)
-                       break;
-               len = eatspace(line + ofs);
-               if ((len == 0) || !is_rfc2822_header(line)) {
-                       /* Re-add the newline */
-                       line[ofs + len] = '\n';
-                       line[ofs + len + 1] = '\0';
-                       break;
-               }
-               ofs += len;
-               /* Yuck, 2822 header "folding" */
+       int len;
+
+       /*
+        * We will read at most (sz-1) bytes and then potentially
+        * re-add NUL after it.  Accessing line[sz] after this is safe
+        * and we can allow len to grow up to and including sz.
+        */
+       sz--;
+
+       /* Get the first part of the line. */
+       if (!fgets(line, sz, in))
+               return 0;
+
+       /*
+        * Is it an empty line or not a valid rfc2822 header?
+        * If so, stop here, and return false ("not a header")
+        */
+       len = eatspace(line);
+       if (!len || !is_rfc2822_header(line)) {
+               /* Re-add the newline */
+               line[len] = '\n';
+               line[len + 1] = '\0';
+               return 0;
+       }
+
+       /*
+        * Now we need to eat all the continuation lines..
+        * Yuck, 2822 header "folding"
+        */
+       for (;;) {
+               int peek, addlen;
+               static char continuation[1000];
+
                peek = fgetc(in); ungetc(peek, in);
                if (peek != ' ' && peek != '\t')
                        break;
+               if (!fgets(continuation, sizeof(continuation), in))
+                       break;
+               addlen = eatspace(continuation);
+               if (len < sz - 1) {
+                       if (addlen >= sz - len)
+                               addlen = sz - len - 1;
+                       memcpy(line + len, continuation, addlen);
+                       len += addlen;
+               }
        }
-       /* Count mbox From headers as headers */
-       if (!ofs && (!memcmp(line, "From ", 5) || !memcmp(line, ">From ", 6)))
-               ofs = 1;
-       return ofs;
+       line[len] = 0;
+
+       return 1;
 }
 
 static int decode_q_segment(char *in, char *ot, char *ep, int rfc2047)
@@ -515,12 +551,9 @@ static void convert_to_utf8(char *line, char *charset)
        char *input_charset = *charset ? charset : latin_one;
        char *out = reencode_string(line, metainfo_charset, input_charset);
 
-       if (!out) {
-               fprintf(stderr, "cannot convert from %s to %s\n",
-                       input_charset, metainfo_charset);
-               *charset = 0;
-               return;
-       }
+       if (!out)
+               die("cannot convert from %s to %s\n",
+                   input_charset, metainfo_charset);
        strcpy(line, out);
        free(out);
 }
@@ -797,18 +830,24 @@ static const char mailinfo_usage[] =
 
 int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 {
+       const char *def_charset;
+
        /* NEEDSWORK: might want to do the optional .git/ directory
         * discovery
         */
        git_config(git_default_config);
 
+       def_charset = (git_commit_encoding ? git_commit_encoding : "utf-8");
+       metainfo_charset = def_charset;
+
        while (1 < argc && argv[1][0] == '-') {
                if (!strcmp(argv[1], "-k"))
                        keep_subject = 1;
                else if (!strcmp(argv[1], "-u"))
-                       metainfo_charset = (git_commit_encoding
-                                           ? git_commit_encoding : "utf-8");
-               else if (!strncmp(argv[1], "--encoding=", 11))
+                       metainfo_charset = def_charset;
+               else if (!strcmp(argv[1], "-n"))
+                       metainfo_charset = NULL;
+               else if (!prefixcmp(argv[1], "--encoding="))
                        metainfo_charset = argv[1] + 11;
                else
                        usage(mailinfo_usage);