Ensure that gen_git_commit_h works even without git.

gen_git_commit_h.ps1

@@ -1,6 +1,6 @@
-$commit = git rev-parse HEAD
-git diff-index --quiet HEAD
-$dirty = $LASTEXITCODE
+$commit = try { git rev-parse HEAD } catch { "unknown" }
+try { git diff-index --quiet HEAD } catch {}
+$dirty = if ($LASTEXITCODE) { "true" } else { "false" }
 echo "#pragma once`r`n#define GIT_COMMIT `"$commit`"`r`n#define GIT_DIRTY $dirty" | out-file -encoding ASCII auto/git_info.h.new
 if (-not (Test-Path .\auto\git_info.h) -or (Compare-Object $(Get-Content .\auto\git_info.h.new) $(Get-Content .\auto\git_info.h))) {
   mv -Force auto/git_info.h.new auto/git_info.h

gen_git_commit_h.sh

@@ -1,8 +1,14 @@
 #!/bin/sh
 cd $(dirname $0)
-commit=$(git rev-parse HEAD)
-git diff-index --quiet HEAD
-dirty=$?
+commit="$(git rev-parse HEAD 2> /dev/null)"
+commit="${commit:-unknown}"
+git diff-index --quiet HEAD 2> /dev/null
+if [ $? -ne 0 ]
+then
+  dirty="true"
+else
+  dirty="false"
+fi
 printf "#pragma once\n#define GIT_COMMIT \"$commit\"\n#define GIT_DIRTY $dirty\n" > auto/git_info.h.new
 if cmp -s auto/git_info.h.new auto/git_info.h 2>&1 > /dev/null
 then

tdutils/td/utils/GitInfo.cpp

@@ -8,11 +8,20 @@
 
 #include "auto/git_info.h"
 
+#if !defined(GIT_COMMIT)
+#define GIT_COMMIT "unknown"
+#endif
+
+#if !defined(GIT_DIRTY)
+#define GIT_DIRTY false
+#endif
+
 namespace td {
 
-CSlice GitInfo::commit() {
+const char *GitInfo::commit() {
   return GIT_COMMIT;
 }
+
 bool GitInfo::is_dirty() {
   return GIT_DIRTY;
 }

tdutils/td/utils/GitInfo.h

@@ -6,13 +6,11 @@
 //
 #pragma once
 
-#include "td/utils/Slice.h"
-
 namespace td {
 
 class GitInfo {
  public:
-  static CSlice commit();
+  static const char *commit();
   static bool is_dirty();
 };