vim-patch:9.0.2064: cannot use buffer-number for errorformat (#25782)

Problem:  cannot use buffer-number for errorformat
Solution: add support for parsing a buffer number using '%b' in
          'errorformat'

closes: vim/vim#13419

b731800522

Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

runtime/doc/quickfix.txt

@@ -1381,6 +1381,7 @@ rest is ignored.  Items can only be 1023 bytes long.
 Basic items
 
 	%f		file name (finds a string)
+	%b		buffer number (finds a number)
 	%o		module name (finds a string)
 	%l		line number (finds a number)
 	%e		end line number (finds a number)
@@ -1420,6 +1421,11 @@ On Windows a leading "C:" will be included in "%f", even when using "%f:".
 This means that a file name which is a single alphabetical letter will not be
 detected.
 
+The "%b" conversion is used to parse a buffer number.  This is useful for
+referring to lines in a scratch buffer or a buffer with no name.  If a buffer
+with the matching number doesn't exist, then that line is used as a non-error
+line.
+
 The "%p" conversion is normally followed by a "^".  It's used for compilers
 that output a line like: >
 	    ^

src/nvim/quickfix.c

@@ -152,7 +152,7 @@ struct qf_info_S {
 static qf_info_T ql_info;         // global quickfix list
 static unsigned last_qf_id = 0;   // Last Used quickfix list id
 
-#define FMT_PATTERNS 13           // maximum number of % recognized
+#define FMT_PATTERNS 14           // maximum number of % recognized
 
 // Structure used to hold the info of one part of 'errorformat'
 typedef struct efm_S efm_T;
@@ -217,6 +217,7 @@ typedef struct {
 
 typedef struct {
   char *namebuf;
+  int bnr;
   char *module;
   char *errmsg;
   size_t errmsglen;
@@ -344,7 +345,7 @@ static int qf_init_process_nextline(qf_list_T *qfl, efm_T *fmt_first, qfstate_T
                       : ((qfl->qf_currfile != NULL && fields->valid)
                          ? qfl->qf_currfile : NULL),
                       fields->module,
-                      0,
+                      fields->bnr,
                       fields->errmsg,
                       fields->lnum,
                       fields->end_lnum,
@@ -391,20 +392,21 @@ static struct fmtpattern {
   char *pattern;
 } fmt_pat[FMT_PATTERNS] = {
   { 'f', ".\\+" },      // only used when at end
-  { 'n', "\\d\\+" },    // 1
-  { 'l', "\\d\\+" },    // 2
-  { 'e', "\\d\\+" },    // 3
-  { 'c', "\\d\\+" },    // 4
-  { 'k', "\\d\\+" },    // 5
-  { 't', "." },         // 6
-#define FMT_PATTERN_M 7
-  { 'm', ".\\+" },      // 7
-#define FMT_PATTERN_R 8
-  { 'r', ".*" },        // 8
-  { 'p', "[- \t.]*" },  // 9
-  { 'v', "\\d\\+" },    // 10
-  { 's', ".\\+" },      // 11
-  { 'o', ".\\+" }       // 12
+  { 'b', "\\d\\+" },    // 1
+  { 'n', "\\d\\+" },    // 2
+  { 'l', "\\d\\+" },    // 3
+  { 'e', "\\d\\+" },    // 4
+  { 'c', "\\d\\+" },    // 5
+  { 'k', "\\d\\+" },    // 6
+  { 't', "." },         // 7
+#define FMT_PATTERN_M 8
+  { 'm', ".\\+" },      // 8
+#define FMT_PATTERN_R 9
+  { 'r', ".*" },        // 9
+  { 'p', "[-\t .]*" },  // 10
+  { 'v', "\\d\\+" },    // 11
+  { 's', ".\\+" },      // 12
+  { 'o', ".\\+" }       // 13
 };
 
 /// Convert an errorformat pattern to a regular expression pattern.
@@ -1312,6 +1314,21 @@ static int qf_parse_fmt_f(regmatch_T *rmp, int midx, qffields_T *fields, int pre
   return QF_OK;
 }
 
+/// Parse the match for buffer number ('%b') pattern in regmatch.
+/// Return the matched value in "fields->bnr".
+static int qf_parse_fmt_b(regmatch_T *rmp, int midx, qffields_T *fields)
+{
+  if (rmp->startp[midx] == NULL) {
+    return QF_FAIL;
+  }
+  int bnr = (int)atol(rmp->startp[midx]);
+  if (buflist_findnr(bnr) == NULL) {
+    return QF_FAIL;
+  }
+  fields->bnr = bnr;
+  return QF_OK;
+}
+
 /// Parse the match for error number ('%n') pattern in regmatch.
 /// Return the matched value in "fields->enr".
 static int qf_parse_fmt_n(regmatch_T *rmp, int midx, qffields_T *fields)
@@ -1496,6 +1513,7 @@ static int qf_parse_fmt_o(regmatch_T *rmp, int midx, qffields_T *fields)
 /// Keep in sync with fmt_pat[].
 static int (*qf_parse_fmt[FMT_PATTERNS])(regmatch_T *, int, qffields_T *) = {
   NULL,  // %f
+  qf_parse_fmt_b,
   qf_parse_fmt_n,
   qf_parse_fmt_l,
   qf_parse_fmt_e,
@@ -1568,6 +1586,7 @@ static int qf_parse_get_fields(char *linebuf, size_t linelen, efm_T *fmt_ptr, qf
   }
 
   fields->namebuf[0] = NUL;
+  fields->bnr = 0;
   fields->module[0] = NUL;
   fields->pattern[0] = NUL;
   if (!qf_multiscan) {

test/old/testdir/test_quickfix.vim

@@ -6320,4 +6320,53 @@ func Test_quickfix_buffer_contents()
   call setqflist([], 'f')
 endfunc
 
+" Test for "%b" in "errorformat"
+func Test_efm_format_b()
+  call setqflist([], 'f')
+  new
+  call setline(1, ['1: abc', '1: def', '1: ghi'])
+  let b1 = bufnr()
+  new
+  call setline(1, ['2: abc', '2: def', '2: ghi'])
+  let b2 = bufnr()
+  new
+  call setline(1, ['3: abc', '3: def', '3: ghi'])
+  let b3 = bufnr()
+  new
+  let lines =<< trim eval END
+    {b1}:1:1
+    {b2}:2:2
+    {b3}:3:3
+  END
+  call setqflist([], ' ', #{lines: lines, efm: '%b:%l:%c'})
+  cfirst
+  call assert_equal([b1, 1, 1], [bufnr(), line('.'), col('.')])
+  cnext
+  call assert_equal([b2, 2, 2], [bufnr(), line('.'), col('.')])
+  cnext
+  call assert_equal([b3, 3, 3], [bufnr(), line('.'), col('.')])
+  enew!
+
+  " Use a non-existing buffer
+  let lines =<< trim eval END
+    9991:1:1:m1
+    9992:2:2:m2
+    {b3}:3:3:m3
+  END
+  call setqflist([], ' ', #{lines: lines, efm: '%b:%l:%c:%m'})
+  cfirst | cnext
+  call assert_equal([b3, 3, 3], [bufnr(), line('.'), col('.')])
+  " Lines with non-existing buffer numbers should be used as non-error lines
+  call assert_equal([
+    \ #{lnum: 0, bufnr: 0, end_lnum: 0, pattern: '', valid: 0, vcol: 0, nr: -1,
+    \   module: '', type: '', end_col: 0, col: 0, text: '9991:1:1:m1'},
+    \ #{lnum: 0, bufnr: 0, end_lnum: 0, pattern: '', valid: 0, vcol: 0, nr: -1,
+    \   module: '', type: '', end_col: 0, col: 0, text: '9992:2:2:m2'},
+    \ #{lnum: 3, bufnr: b3, end_lnum: 0, pattern: '', valid: 1, vcol: 0,
+    \   nr: -1, module: '', type: '', end_col: 0, col: 3, text: 'm3'}],
+    \ getqflist())
+  %bw!
+  call setqflist([], 'f')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab