1 files changed, 167 insertions, 43 deletions

diff --git a/src/nvim/sign.c b/src/nvim/sign.c
index 23dd447744..ab5d04d39b 100644
--- a/src/nvim/sign.c
+++ b/src/nvim/sign.c
@@ -198,7 +198,7 @@ static void insert_sign(
     // column for signs.
     if (buf->b_signlist == NULL) {
       redraw_buf_later(buf, NOT_VALID);
-      changed_cline_bef_curs();
+      changed_line_abv_curs();
     }
 
     // first sign in signlist
@@ -265,6 +265,81 @@ dict_T * sign_get_info(signlist_T *sign)
   return d;
 }
 
+// Sort the signs placed on the same line as "sign" by priority.  Invoked after
+// changing the priority of an already placed sign.  Assumes the signs in the
+// buffer are sorted by line number and priority.
+static void sign_sort_by_prio_on_line(buf_T *buf, signlist_T *sign)
+  FUNC_ATTR_NONNULL_ALL
+{
+  // If there is only one sign in the buffer or only one sign on the line or
+  // the sign is already sorted by priority, then return.
+  if ((sign->prev == NULL
+       || sign->prev->lnum != sign->lnum
+       || sign->prev->priority > sign->priority)
+      && (sign->next == NULL
+          || sign->next->lnum != sign->lnum
+          || sign->next->priority < sign->priority)) {
+    return;
+  }
+
+  // One or more signs on the same line as 'sign'
+  // Find a sign after which 'sign' should be inserted
+
+  // First search backward for a sign with higher priority on the same line
+  signlist_T *p = sign;
+  while (p->prev != NULL
+         && p->prev->lnum == sign->lnum
+         && p->prev->priority <= sign->priority) {
+    p = p->prev;
+  }
+  if (p == sign) {
+    // Sign not found. Search forward for a sign with priority just before
+    // 'sign'.
+    p = sign->next;
+    while (p->next != NULL
+           && p->next->lnum == sign->lnum
+           && p->next->priority > sign->priority) {
+      p = p->next;
+    }
+  }
+
+  // Remove 'sign' from the list
+  if (buf->b_signlist == sign) {
+    buf->b_signlist = sign->next;
+  }
+  if (sign->prev != NULL) {
+    sign->prev->next = sign->next;
+  }
+  if (sign->next != NULL) {
+    sign->next->prev = sign->prev;
+  }
+  sign->prev = NULL;
+  sign->next = NULL;
+
+  // Re-insert 'sign' at the right place
+  if (p->priority <= sign->priority) {
+    // 'sign' has a higher priority and should be inserted before 'p'
+    sign->prev = p->prev;
+    sign->next = p;
+    p->prev = sign;
+    if (sign->prev != NULL) {
+      sign->prev->next = sign;
+    }
+    if (buf->b_signlist == p) {
+      buf->b_signlist = sign;
+    }
+  } else {
+    // 'sign' has a lower priority and should be inserted after 'p'
+    sign->prev = p;
+    sign->next = p->next;
+    p->next = sign;
+    if (sign->next != NULL) {
+      sign->next->prev = sign;
+    }
+  }
+}
+
+
 /// Add the sign into the signlist. Find the right spot to do it though.
 void buf_addsign(
     buf_T *buf,     // buffer to store sign in
@@ -284,6 +359,8 @@ void buf_addsign(
         && sign_in_group(sign, groupname)) {
       // Update an existing sign
       sign->typenr = typenr;
+      sign->priority = prio;
+      sign_sort_by_prio_on_line(buf, sign);
       return;
     } else if (lnum < sign->lnum) {
       insert_sign_by_lnum_prio(buf, prev, id, groupname, prio, lnum, typenr);
@@ -418,11 +495,11 @@ linenr_T buf_delsign(
     }
   }
 
-  // When deleted the last sign needs to redraw the windows to remove the
-  // sign column.
+  // When deleting the last sign the cursor position may change, because the
+  // sign columns no longer shows.  And the 'signcolumn' may be hidden.
   if (buf->b_signlist == NULL) {
     redraw_buf_later(buf, NOT_VALID);
-    changed_cline_bef_curs();
+    changed_line_abv_curs();
   }
 
   return lnum;
@@ -495,7 +572,7 @@ void buf_delete_signs(buf_T *buf, char_u *group)
     // When deleting the last sign need to redraw the windows to remove the
     // sign column. Not when curwin is NULL (this means we're exiting).
     if (buf->b_signlist != NULL && curwin != NULL) {
-      changed_cline_bef_curs();
+      changed_line_abv_curs();
     }
 
     lastp = &buf->b_signlist;
@@ -754,6 +831,14 @@ int sign_define_by_name(
     } else {
       sp_prev->sn_next = sp;
     }
+  } else {
+    // Signs may already exist, a redraw is needed in windows with a
+    // non-empty sign list.
+    FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+      if (wp->w_buffer->b_signlist != NULL) {
+        redraw_buf_later(wp->w_buffer, NOT_VALID);
+      }
+    }
   }
 
   // set values for a defined sign.
@@ -1531,10 +1616,44 @@ static enum
     EXP_SUBCMD,   // expand :sign sub-commands
     EXP_DEFINE,   // expand :sign define {name} args
     EXP_PLACE,    // expand :sign place {id} args
+    EXP_LIST,     // expand :sign place args
     EXP_UNPLACE,  // expand :sign unplace"
-    EXP_SIGN_NAMES  // expand with name of placed signs
+    EXP_SIGN_NAMES,   // expand with name of placed signs
+    EXP_SIGN_GROUPS,  // expand with name of placed sign groups
 } expand_what;
 
+// Return the n'th sign name (used for command line completion)
+static char_u *get_nth_sign_name(int idx)
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
+{
+  // Complete with name of signs already defined
+  int current_idx = 0;
+  for (sign_T *sp = first_sign; sp != NULL; sp = sp->sn_next) {
+    if (current_idx++ == idx) {
+      return sp->sn_name;
+    }
+  }
+  return NULL;
+}
+
+// Return the n'th sign group name (used for command line completion)
+static char_u *get_nth_sign_group_name(int idx)
+{
+  // Complete with name of sign groups already defined
+  int current_idx = 0;
+  int todo = (int)sg_table.ht_used;
+  for (hashitem_T *hi = sg_table.ht_array; todo > 0; hi++) {
+    if (!HASHITEM_EMPTY(hi)) {
+      todo--;
+      if (current_idx++ == idx) {
+        signgroup_T *const group = HI2SG(hi);
+        return group->sg_name;
+      }
+    }
+  }
+  return NULL;
+}
+
 /// Function given to ExpandGeneric() to obtain the sign command
 /// expansion.
 char_u * get_sign_name(expand_T *xp, int idx)
@@ -1552,20 +1671,18 @@ char_u * get_sign_name(expand_T *xp, int idx)
                               "buffer=", NULL };
         return (char_u *)place_arg[idx];
       }
+    case EXP_LIST: {
+      char *list_arg[] = { "group=", "file=", "buffer=", NULL };
+      return (char_u *)list_arg[idx];
+    }
     case EXP_UNPLACE: {
         char *unplace_arg[] = { "group=", "file=", "buffer=", NULL };
         return (char_u *)unplace_arg[idx];
       }
-    case EXP_SIGN_NAMES: {
-        // Complete with name of signs already defined
-        int current_idx = 0;
-        for (sign_T *sp = first_sign; sp != NULL; sp = sp->sn_next) {
-          if (current_idx++ == idx) {
-            return sp->sn_name;
-          }
-        }
-      }
-      return NULL;
+    case EXP_SIGN_NAMES:
+      return get_nth_sign_name(idx);
+    case EXP_SIGN_GROUPS:
+      return get_nth_sign_group_name(idx);
     default:
       return NULL;
   }
@@ -1574,7 +1691,6 @@ char_u * get_sign_name(expand_T *xp, int idx)
 /// Handle command line completion for :sign command.
 void set_context_in_sign_cmd(expand_T *xp, char_u *arg)
 {
-  char_u  *p;
   char_u  *end_subcmd;
   char_u  *last;
   int    cmd_idx;
@@ -1598,26 +1714,6 @@ void set_context_in_sign_cmd(expand_T *xp, char_u *arg)
   //                |
   //                begin_subcmd_args
   begin_subcmd_args = skipwhite(end_subcmd);
-  p = skiptowhite(begin_subcmd_args);
-  if (*p == NUL) {
-    //
-    // Expand first argument of subcmd when possible.
-    // For ":jump {id}" and ":unplace {id}", we could
-    // possibly expand the ids of all signs already placed.
-    //
-    xp->xp_pattern = begin_subcmd_args;
-    switch (cmd_idx) {
-      case SIGNCMD_LIST:
-      case SIGNCMD_UNDEFINE:
-        // :sign list <CTRL-D>
-        // :sign undefine <CTRL-D>
-        expand_what = EXP_SIGN_NAMES;
-        break;
-      default:
-        xp->xp_context = EXPAND_NOTHING;
-    }
-    return;
-  }
 
   // Expand last argument of subcmd.
   //
@@ -1626,6 +1722,7 @@ void set_context_in_sign_cmd(expand_T *xp, char_u *arg)
   //              p
 
   // Loop until reaching last argument.
+  char_u *p = begin_subcmd_args;
   do {
     p = skipwhite(p);
     last = p;
@@ -1645,7 +1742,20 @@ void set_context_in_sign_cmd(expand_T *xp, char_u *arg)
         expand_what = EXP_DEFINE;
         break;
       case SIGNCMD_PLACE:
-        expand_what = EXP_PLACE;
+        // List placed signs
+        if (ascii_isdigit(*begin_subcmd_args)) {
+          //   :sign place {id} {args}...
+          expand_what = EXP_PLACE;
+        } else {
+          //   :sign place {args}...
+          expand_what = EXP_LIST;
+        }
+        break;
+      case SIGNCMD_LIST:
+      case SIGNCMD_UNDEFINE:
+        // :sign list <CTRL-D>
+        // :sign undefine <CTRL-D>
+        expand_what = EXP_SIGN_NAMES;
         break;
       case SIGNCMD_JUMP:
       case SIGNCMD_UNPLACE:
@@ -1659,19 +1769,33 @@ void set_context_in_sign_cmd(expand_T *xp, char_u *arg)
     xp->xp_pattern = p + 1;
     switch (cmd_idx) {
       case SIGNCMD_DEFINE:
-        if (STRNCMP(last, "texthl", p - last) == 0
-            || STRNCMP(last, "linehl", p - last) == 0
-            || STRNCMP(last, "numhl", p - last) == 0) {
+        if (STRNCMP(last, "texthl", 6) == 0
+            || STRNCMP(last, "linehl", 6) == 0
+            || STRNCMP(last, "numhl", 5) == 0) {
           xp->xp_context = EXPAND_HIGHLIGHT;
-        } else if (STRNCMP(last, "icon", p - last) == 0) {
+        } else if (STRNCMP(last, "icon", 4) == 0) {
           xp->xp_context = EXPAND_FILES;
         } else {
           xp->xp_context = EXPAND_NOTHING;
         }
         break;
       case SIGNCMD_PLACE:
-        if (STRNCMP(last, "name", p - last) == 0) {
+        if (STRNCMP(last, "name", 4) == 0) {
           expand_what = EXP_SIGN_NAMES;
+        } else if (STRNCMP(last, "group", 5) == 0) {
+          expand_what = EXP_SIGN_GROUPS;
+        } else if (STRNCMP(last, "file", 4) == 0) {
+          xp->xp_context = EXPAND_BUFFERS;
+        } else {
+          xp->xp_context = EXPAND_NOTHING;
+        }
+        break;
+      case SIGNCMD_UNPLACE:
+      case SIGNCMD_JUMP:
+        if (STRNCMP(last, "group", 5) == 0) {
+          expand_what = EXP_SIGN_GROUPS;
+        } else if (STRNCMP(last, "file", 4) == 0) {
+          xp->xp_context = EXPAND_BUFFERS;
         } else {
           xp->xp_context = EXPAND_NOTHING;
         }