Merge pull request #13807 from spywhere/min-size-auto-sign

Auto sign column with minimum size support

3 files changed, 147 insertions, 3 deletions

diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 2a757bbed9..a497efa47e 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -5536,6 +5536,12 @@ A jump table for the options with a short description can be found at |Q_op|.
 	   "auto"   	only when there is a sign to display
 	   "auto:[1-9]" resize to accommodate multiple signs up to the
 	                given number (maximum 9), e.g. "auto:4"
+	   "auto:[1-8]-[2-9]"
+	                resize to accommodate multiple signs up to the
+			given maximum number (maximum 9) while keeping
+			at least the given minimum (maximum 8) fixed
+			space. The minimum number should always be less
+			than the maximum number, e.g. "auto:2-5"
 	   "no"	    	never
 	   "yes"    	always
 	   "yes:[1-9]"  always, with fixed space for signs up to the given
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 47b9e9bb07..74bf6f0590 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2913,7 +2913,7 @@ ambw_end:
 #endif
   } else if (varp == &curwin->w_p_scl) {
     // 'signcolumn'
-    if (check_opt_strings(*varp, p_scl_values, false) != OK) {
+    if (check_signcolumn(*varp) != OK) {
       errmsg = e_invarg;
     }
     // When changing the 'signcolumn' to or from 'number', recompute the
@@ -3232,6 +3232,34 @@ static int int_cmp(const void *a, const void *b)
   return *(const int *)a - *(const int *)b;
 }
 
+/// Handle setting 'signcolumn' for value 'val'
+///
+/// @return OK when the value is valid, FAIL otherwise
+int check_signcolumn(char_u *val)
+{
+  // check for basic match
+  if (check_opt_strings(val, p_scl_values, false) == OK) {
+    return OK;
+  }
+
+  // check for 'auto:<NUMBER>-<NUMBER>'
+  if (STRLEN(val) == 8
+      && !STRNCMP(val, "auto:", 5)
+      && ascii_isdigit(val[5])
+      && val[6] == '-'
+      && ascii_isdigit(val[7])
+      ) {
+    int min = val[5] - '0';
+    int max = val[7] - '0';
+    if (min < 1 || max < 2 || min > 8 || max > 9 || min >= max) {
+      return FAIL;
+    }
+    return OK;
+  }
+
+  return FAIL;
+}
+
 /// Handle setting 'colorcolumn' or 'textwidth' in window "wp".
 ///
 /// @return error message, NULL if it's OK.
@@ -7095,7 +7123,7 @@ int csh_like_shell(void)
 /// buffer signs and on user configuration.
 int win_signcol_count(win_T *wp)
 {
-  int maximum = 1, needed_signcols;
+  int minimum = 0, maximum = 1, needed_signcols;
   const char *scl = (const char *)wp->w_p_scl;
 
   // Note: It checks "no" or "number" in 'signcolumn' option
@@ -7119,9 +7147,14 @@ int win_signcol_count(win_T *wp)
   if (!strncmp(scl, "auto:", 5)) {
     // Variable depending on a configuration
     maximum = scl[5] - '0';
+    // auto:<NUM>-<NUM>
+    if (strlen(scl) == 8 && *(scl + 6) == '-') {
+      minimum = maximum;
+      maximum = scl[7] - '0';
+    }
   }
 
-  return MIN(maximum, needed_signcols);
+  return MAX(minimum, MIN(maximum, needed_signcols));
 }
 
 /// Get window or buffer local options
diff --git a/test/functional/ui/sign_spec.lua b/test/functional/ui/sign_spec.lua
index d1b8de5e4e..1937102782 100644
--- a/test/functional/ui/sign_spec.lua
+++ b/test/functional/ui/sign_spec.lua
@@ -266,6 +266,111 @@ describe('Signs', function()
       ]]}
     end)
 
+    it('auto-resize sign column with minimum size (#13783)', function()
+      feed('ia<cr>b<cr>c<cr><esc>')
+      command('set number')
+      -- sign column should always accommodate at the minimum size
+      command('set signcolumn=auto:1-3')
+      screen:expect([[
+        {2:  }{6:  1 }a                                              |
+        {2:  }{6:  2 }b                                              |
+        {2:  }{6:  3 }c                                              |
+        {2:  }{6:  4 }^                                               |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+                                                             |
+      ]])
+      -- should support up to 8 signs at minimum
+      command('set signcolumn=auto:8-9')
+      screen:expect([[
+        {2:                }{6:  1 }a                                |
+        {2:                }{6:  2 }b                                |
+        {2:                }{6:  3 }c                                |
+        {2:                }{6:  4 }^                                 |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+                                                             |
+      ]])
+      -- should keep the same sign size when signs are not exceeding
+      -- the minimum
+      command('set signcolumn=auto:2-5')
+      command('sign define pietSearch text=>> texthl=Search')
+      command('sign place 1 line=1 name=pietSearch buffer=1')
+      screen:expect([[
+        {1:>>}{2:  }{6:  1 }a                                            |
+        {2:    }{6:  2 }b                                            |
+        {2:    }{6:  3 }c                                            |
+        {2:    }{6:  4 }^                                             |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+                                                             |
+      ]])
+      -- should resize itself when signs are exceeding minimum but
+      -- not over the maximum
+      command('sign place 2 line=1 name=pietSearch buffer=1')
+      command('sign place 3 line=1 name=pietSearch buffer=1')
+      command('sign place 4 line=1 name=pietSearch buffer=1')
+      screen:expect([[
+        {1:>>>>>>>>}{6:  1 }a                                        |
+        {2:        }{6:  2 }b                                        |
+        {2:        }{6:  3 }c                                        |
+        {2:        }{6:^  4 }                                         |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+                                                             |
+      ]])
+      -- should keep the column at maximum size when signs are
+      -- exceeding the maximum
+      command('sign place 5 line=1 name=pietSearch buffer=1')
+      command('sign place 6 line=1 name=pietSearch buffer=1')
+      command('sign place 7 line=1 name=pietSearch buffer=1')
+      command('sign place 8 line=1 name=pietSearch buffer=1')
+      screen:expect([[
+        {1:>>>>>>>>>>}{6:  1 }a                                      |
+        {2:          }{6:  2 }b                                      |
+        {2:          }{6:  3 }c                                      |
+        {2:        ^  }{6:  4 }                                       |
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+        {0:~                                                    }|
+                                                             |
+      ]])
+    end)
+
     it('ignores signs with no icon and text when calculting the signcolumn width', function()
       feed('ia<cr>b<cr>c<cr><esc>')
       command('set number')