Improve git show highlighting

[scop]

git show output is currently detected and highlighted as gitlog, which means the diff part is not highlighted. Would be great if both of them would be.

[keith-hall]

I have played around with the Git Log syntax definition, and have added support for highlighting diffs - the patch (including the fix for #1632) is:

--- Shipped Packages/Git Formats/Git Log.sublime-syntax	2021-04-02 13:30:54
+++ Packages/Git Formats/Git Log.sublime-syntax	2021-07-16 23:43:48
@@ -13,13 +13,37 @@
   main:
     # 1st header line
     # commit d9d9fb804f5d61c13ba2f8746af33a9f3c609075
-    - match: (?:(commit)\s+(\h{7,}))?\s*\n
-      scope: meta.header.git.commit markup.raw.block.git.log
+    - match: ^(commit)\s+(\h{7,})
       captures:
         1: keyword.other.commit.git.log
         2: constant.other.hash.git.log
-      embed: commit-header
-      escape: (?=^commit\s)
+      push:
+        - meta_scope: meta.header.git.commit markup.raw.block.git.log
+        - match: $\n?
+          scope: meta.header.git.commit markup.raw.block.git.log
+          pop: true
+          embed: commit-header
+          escape: (?=^(?:commit|diff)\s)
+        - match: (\()(HEAD)\s*(->)
+          captures:
+            1: punctuation.section.parens.begin.git.log
+            2: support.type.git.log
+            3: punctuation.separator.mapping.git.log
+          push:
+            - match: \)
+              scope: punctuation.section.parens.end.git.log
+              pop: true
+            - match: \bmaster\b
+              scope: entity.other.branch-name.master.git.log
+            - match: (\w+)(?:(/)(\w+))?
+              scope: entity.other.branch-name.git.log
+            - match: ','
+              scope: punctuation.separator.sequence.git.log
+    - match: '^(?=diff\s)'
+      embed: scope:source.shell.bash
+      escape: $
+    - match: (?=^index\s)
+      set: scope:source.diff
 
   commit-header:
     # All header attributes are mappings of `key: value` format.

and here's an example of how bat renders it with these changes: (it looks better in ST, my color scheme there targets more scopes with colors I guess)

I will try to make a PR to the Packages repo with these changes soon ™️

[arcnmx]

The relevant PR to packages was merged quickly, is this still blocked on supporting newer syntax features?

[keith-hall]

Yeah, we can't straight up bump the submodule version used due to #2358.
But perhaps we can apply individual patches which are compatible. It just seems like a maintenance nightmare to me though.
Perhaps if someone else were to take on the work... ;) #919